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JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

Vol 43 JULY, 1944 No. 1 



CONTENTS 

PAGE 

Report of the Engineering Vice-President on Standardi- 
zation D. E. HYNDMAN 1 
The Role of the American Standards Association in War 

Standardization J. W. McNAiR 5 

Some Fundamental Considerations in Military Amplifier 

Design S. L. CHERTOK 10 

Report of Subcommittee B on 16-Mm Sound 

J. A. MAURER 19 
Report of Subcommittee C on 16-Mm Laboratory 

Practice M. R. BOYER 21 

Report of Subcommittee D on 16-Mm Projection 

A. G. ZIMMERMAN 23 
Report of Subcommittee G on Exposure Meters 

J. M. WHITTENTON 25 
A Film for Measuring Projector Steadiness 

M. G. TOWNSLEY 30 
The Effect of Lamp Filament Position on Projection 

Screen Brightness Uniformity M. G. TOWNSLEY 37 

A Method for Measuring the Steadiness of Motion 

Picture Cameras M. G. TOWNSLEY 45 

A New Mobile Recording Unit for Studio and Location 

Work J. L. FIELDS 51 

Note on the Evaluation of Photographic Speed from 

Sensitometric Data C. TUTTLE 59 

Technical News 67 

Society Announcements 72 

(The Society is not responsible for statements of authors.) 

Contents of previous issues of the JOURNAL are indexed in the 
Industrial Arts Index available in public libraries. 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

HARRY SMITH, JR., EDITOR 

ARTHUR C. DOWNES, Chairman 

Board of Editors 

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KELLOGG 
CLYDE R. KEITH ALAN M. GUNDELFINGER CHARLES W. HANDLEY 

ARTHUR C. HARDY 
Officers of the Society 
*President: HERBERT GRIFFIN, 

133 E. Santa Anita Ave., Burbank, Calif. 
*Past-President: EMERY HUSE, 

6706 Santa Monica Blvd., Hollywood, Calif. 
^Executive Vice-President: LOREN L. RYDER, 

5451 Marathon St., Hollywood, Calif. 
** Engineering Vice-President: DONALD E. HYNDMAN, 

350 Madison Ave., New York, N. Y. 
*Editorial Vice-President: ARTHUR C. DOWNES, 

Box 6087, Cleveland, Ohio. 

** Financial Vice-President: ARTHUR S. DICKINSON, 
28 W. 44th St., New York, N. Y. 

* Convention V ice-President: WILLIAM C. KUNZMANN, 

Box 6087, Cleveland, Ohio. 
^Secretary: E. ALLAN WILLIFORD, 

30 E. 42d St., New York, N. Y. 
^Treasurer: M. R. BOYER 

350 Fifth Ave., New York, N. Y. 

Governors 

**FRANK E. CARLSON, Nela Park, Cleveland, Ohio. 
*fCHARLES W. HANDLEY, 1960 W. 84th St., Los Angeles, Calif. 
**EDWARD M. HONAN, 6601 Romaine St., Hollywood, Calif. 
*JCLYDE R. KEITH, 195 Broadway, New York, N. Y. . 
**JOHN A. MAURER, 117 E. 24th St., New York, N. Y. 
*HOLLIS W. MOYSE, 6656 Santa Monica Blvd., Hollywood, Calif. 
*WILLIAM A. MUELLER, 4000 W. Olive Ave., Burbank, Calif. 
*H. W. REMERSHIED, 716 N. La Brea St., Hollywood, Calif. 
**EARL I. SPONABLE, 460 W. 54th St., New York, N. Y. 

* JOSEPH H. SPRAY, 1277 E. 14th St., Brooklyn, N. Y. 
*REEVE O. STROCK, 111 Eighth Ave., New York, N. Y. 

**WALLACE V. WOLFE, 1016 N. Sycamore St., Hollywood, Calif. 

*Term expires December 31, 1944. 
**Term expires December 31, 1945. 
tChairman, Pacific Coast Section. 
JChairman, Atlantic Coast Section. 



Subscription to non-members, $8.00 per annum; to members, $5.00 per annum, included 
in their annual membership dues; single copies, $1.00. A discount on subscription or single 
copies of 15j>er cent is allowed to accredited agencies. Order from the Society of Motion Picture 
Engineers, Inc., Hotel Pennsylvania, New York 1, N. Y. 

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers, Inc. 

Publication Office, 20th & Northampton Sts., Easton, Pa. 

General and Editorial Office, Hotel Pennsylvania, New York 1, N. Y. 

Entered as second-class matter January 15, 1930, at the Post Office at Easton, 

Pa., under the Act of March 3, 1879. Copyrighted, 1944, by the Society of Motion 

Picture Engineers. Inc. 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

Vol 43 JULY, 1944 No. 1 



REPORT OF THE ENGINEERING VICE-PRESIDENT ON 
STANDARDIZATION * 



D. E. HYNDMAN** 

The procedure necessary for the formulation of War Standards for 
Motion Picture Equipment and Processes was described in an earlier 
paper which has appeared in the April, 1944, issue of the JOURNAL of 
the Society of Motion Picture Engineers, pages 211-229. The plan- 
ning, initiation and prosecution of the major project of the prepara- 
tion, study and issuance of the corresponding specifications have 
afforded the Society of Motion Picture Engineers an opportunity to 
collaborate both with the military forces, the War Production Board 
and the motion picture industry along lines which, it is believed, 
have been of constructive assistance to the war effort. 

In this report, there will be discussed the nature and course of the 
work which has been carried on since the activities of the ASA War 
Standards Committee on Photography and Cinematography-Z52 
were initiated. 

Prior to such detailed consideration, it is desirable to outline the 
major elements necessary to the success of a plan for wartime speci- 
fications of complex products needed by the Armed Forces. These 
elements include : 

(1) The formulation by the military forces of their needs, usually 
in the form of a list of the products and methods for which specifica- 
tions are desired, as well as the scope, degree of detail, method of 
presentation, and field of application of a corresponding specification. 
It was fortunate that the U. S. Army Signal Corps, U. S. Army 
Air Forces, U. S. Army Engineer Corps, Bureau of Aeronautics, 
U. S. Navy, and U. S. Marine Corps were prepared to present 
their problems and needs in detail. Particularly active in this 

* Presented Apr. 19, 1944, at the Technical Conference in New York. 
** Engineering Vice-President, Society of Motion Picture Engineers, 



2 D. E. HYNDMAN Vol 43, No. 1 

regard were all the members of the present Armed Forces Com- 
mittee. 

(2) The availability of committees or groups of highly skilled 
engineers and technical men active in the field of development and 
production of the devices needed by the military services, such 
groups being preferably of long standing and experience and accord- 
ingly ready to organize and prepare on short notice to attack and solve 
problems of a nature generally similar to those which they have been 
previously considering. 

By great good fortune, the SMPE was in an excellent position to 
make available to the military services, or any other appropriate 
agency, the long experience and skill of its various committees and 
subcommittees active in certain fields. The Engineering Vice- 
President of the Society, in conjunction with the Chairman of the 
Committee on Standards, Mr. F. T. Bowditch; the Chairman of the 
ASA Sectional Committee on Motion Pictures-Z22, Dr. Alfred N. 
Goldsmith; and the future Chairman of the Armed Forces Com- 
mittee, Capt. Lloyd T. Goldsmith, had arranged for the organiza- 
tion or continuation of the activities of a major group of engineering 
committees of the Society which, with expanded membership, proved 
highly effective in the type of specification preparation required by 
the military services. 

The roster of the Society's committees was examined and the 
following committees and their chairmen were selected as ready and 
suitable for this work. Accordingly, it is desired at this time to 
express the thanks of the Society and its officers for the loyal and 
willing service rendered by the chairmen and membership of the fol- 
lowing committees : 

Committee Chairman 

Subcommittee A on 16-Mm Cinematography (Z52) J. B. Contner 

Subcommittee B on 16-Mm Sound (Z52) J. A. Maurer 

Subcommittee C on 16-Mm Laboratory Practice (Z52) M. R. Boyer 

Subcommittee D on 16-Mm Projection (Z52) A. G. Zimmerman 

It is certain that but for the immediate availability of these com- 
mittees, their chairmen and their membership, it would have been 
difficult indeed to have undertaken the necessary tasks of equipment 
and method specifications for the military services which were ur- 
gently required. 

(3) The sponsorship of the entire specification project by a govern- 
mental agency in a position to render guidance and financial support 



July, 1944 REPORT OF ENGINEERING VICE-PRESIDENT 3 

to the project, as well as the existence and availability of a standardiz- 
ing body of long experience capable of acting as the secretariat of 
the various specification groups or committees. The task of prepa- 
ration of specifications involves complexities, need for manpower, 
and incidental facilities and cost which are usually not fully appre- 
ciated by those undertaking a task of such magnitude. The SMPE 
is thoroughly capable of handling normal standardization projects 
in peacetime at a reasonable rate of progress which is all that is 
required under such circumstances. It is unlikely, however, that 
the Society could have provided the clerical and technical force neces- 
sary to act as an effective secretariat for the specification committees 
under the conditions of greatly accelerated operation and widely 
expanded scope and detail requisite for specifications needed under 
wartime conditions by the military services. 

However, the American Standards Association had previously 
been engaged in a War Standards project of somewhat similar nature 
to that here under consideration. Its expense in these directions 
was extensive and its staff adequate to handle all secretarial and cleri- 
cal activities. Furthermore, it had enjoyed the financial backing of 
the War Production Board in this earlier War Standards project, 
and had demonstrated its capability of handling such a secretariat 
within acceptable financial limitations. 

Dr. Alfred N. Goldsmith (member, Committee on Standards) 
had been actively engaged in the earlier project mentioned under 
this heading and was acquainted with the problems which were in- 
volved. He suggested that the Committee on Standards of the 
SMPE and the Armed Forces enter into corresponding arrangements 
with the War Production Board, as a financial sponsor, and the 
American Standards Association, as a secretariat, in order to speed up 
the project and to insure its successful handling. 

(4)- Adequate representation of all individuals, groups, engineering 
societies, as well as interested individuals of specific phases of the 
motion picture industry are essential as membership on committees 
to assure unification and agreement on specifications that would re- 
ceive general acceptance. In the undertaking, the facilities of the 
Research Council of the Academy of Motion Picture Arts and 
Sciences, manufacturers of equipment, motion picture film, acces- 
sories, and processing plants (motion picture laboratories) were re- 
quested to assist in the task as cooperative workers. 

These elements have all been coordinated and have been working 



4 D. E. HYNDMAN 

together in the unified effort of producing specifications in accord 
with the requirements of the Armed Forces. Progress has been 
steadily forward for the past 4 months which will continue as long as 
the Armed Forces have demands to be satisfied by specification 
preparation. The following presentations of progress reports of the 
chairmen of various subcommittees of ASA War Standards Com- 
mittee on Photography and Cinematography-Z52 will fully show the 
status of specification work on a number of assignments. The re- 
sults of the work reported will illustrate the magnitude of the task, 
the ability of the personnel involved and the cooperative spirit. 



THE ROLE OF THE AMERICAN STANDARDS ASSOCIATION 
IN WAR STANDARDIZATION* 



J. W. McNAIR 1 



It may be a surprise to many of today's SMPE members that 
standardization was probably the most important reason for the 
founding of the Society. A reading of the early issues of the Trans- 
actions of the Society, following its founding in 1916, shows a pre- 
ponderance of articles (now called by the more dignified title of papers) 
on the subject of standardization. To cite just a few instances at 
random, in the second issue of the Transactions there is an article on 
the importance of precision in the manufacture of cine machinery 
and film, and another article setting forth suggested standard dimen- 
sions for slitting and perforating 35-mm film which are substantially 
the dimensions in use today. 

It is interesting to note that one of the most comprehensive papers 
which Dr. P. G. Agnew, Secretary of the American Standards Asso- 
ciation, has presented to date is one entitled "National Standardiza- 
tion in America," which was presented before the Spring Meeting 
of the SMPE in 1933 and appears in the October, 1933, JOURNAL. 
Much of the material contained in this article was repeated in a 
subsequent article by the same author for the Encyclopaedia Britan- 
nica. 

It has been said that the most standard thing in the world is 35-mm 
film. There is no doubt that a print of a 35-mm film wherever manu- 
factured will, if made in accordance with existing standards and trade 
practices, project satisfactorily anywhere in the world. Dimensions 
have been "tied down" and in the case of 35-mm sound film, the 
Research Council of the Academy of Motion Picture Arts and 
Sciences has even suggested a recommended sound projection char- 
acteristic that has been used for more than 7 years as a reference in 
theaters. With such standardization and crystallization of trade 

* Presented Apr. 19, 1944, at the Technical Conference in New York. 
** Secretary, ASA War Committee on Photography and Cinematography-Z52. 



6 J. W. McNAlR Vol 43, No. 1 

practices, it is no wonder that both picture and sound from a Holly- 
wood-produced 35-mm film will be satisfactory technically when run 
in any theater on equipment that has been kept in proper adjustment. 

It is obvious that such a desirable state of performance was not 
achieved merely by promulgating a recommended projection fre- 
quency characteristic for the theater equipment used; the whole 
process had to be integrated to make certain that any film would 
project satisfactorily in any theater. The recommended frequency 
characteristic was a good starting point for sound in the theater; 
it was simple and easily applied. The varieties of equipments in use 
were few; practically all the sound equipment, for example, used high- 
efficiency, horn-type loud-speakers, the technical characteristics of 
which were well known. If a film projected on such equipment was 
unsatisfactory in quality, it was the film that was changed to correct 
the difficulty. Under these circumstances, attempted correction at 
the wrong point in the system was avoided. Thus, the combination 
of a good film and good equipment was bound to be productive of a 
good result. 

Unfortunately this happy state of affairs did not prevail when 
the Armed Forces decided to use 16-mm equipment. The available 
production capacity for 16-mm films and equipment was relatively 
small just before the war; the war has accelerated production of these 
items in pretty much the same manner as it has accelerated radio and 
other electronic equipment. The standardization job on electronics 
had to come first; it is used right up in the front line beside weapons. 
We have had well over 2 years' experience with radio standardization 
and now it is 16-mm's turn. We hope to be able to benefit in our 
motion picture standardization from our previous experience in radio 
standardization and, if possible, use identical component parts with 
identical stock numbers. In the case of resistors and capacitors, for 
example, we should be able to do so quite readily as the performance 
requirements are similar. 

And now let me say a few brief words about construction. The 
beating that military equipment must take if it is to operate success- 
fully at its point of use is widely known. Military equipment is 
usually transported in carrying cases of the kind indicated in the 
third (and most recent draft) of the 16-mm projector specification 
that has just been completed. If you will remember that an enlisted 
man who picks up a carrying case often does not have the slightest 
idea as to what is inside, you can well understand why it gets such a 



July, 1944 AMERICAN STANDARDS ASSOCIATION IN WAR 7 

beating. When you put equipment into a carrying case, you can 
assume that it will be handled no better than a case of "canned 
willy" (corned beef, to you) and it may well be that "GI Joe" 
doesn't like corned willy anyway! 

Little things are important. You can obtain an idea of the 
importance of characteristics of fixed composition resistors when you 
read over the ASA Specification for Fixed Composition Resistors 
C75.7-1943 of which there were 9 drafts; each set of meetings that 
resulted in a draft required the undivided attention of about 20 to 30 
men; all of the men were specialists, and each draft required countless 
man-hours on the part of the ASA to collect and set up the data in 
specification form. And yet all this effort was expended (and well- 
spent, too) for an article that sells at 2 or 3 cents! These specifica- 
tions are completed and now may be used to describe the composition 
resistors which are to be used where applicable in the new 16-mm 
military model projector. 

Standardization gets its biggest push during war; the tempo 
in peacetime is quite slow by comparison. During peacetime 
standardization is of concern indirectly to all of us, and the pro- 
cedure of the American Standards Association represents a joint 
enterprise of the material trade associations, technical societies, and 
governmental groups together with a cross section of American in- 
dustry itself. At the present time more than 3000 individuals are 
enrolled on the committees that are developing new standards or 
revising standards already in use. 

These committees are like miniature technical legislatures set up 
along industrial lines. The problems to be solved are broken down 
into parts small enough so that each part can be handled by one of 
the committees made up of representatives of all groups substantially 
concerned with the standard. Every effort is made to reach a solu- 
tion rather than a mere compromise; a consensus of technical opinion 
rather than a mere majority vote is the objective. It is only in this 
progressive way that wide acceptance of the standard can be as- 
sured with the minimum of delay and the optimum in technical de- 
sirability. 

American War Standards follow substantially the same plan. 
As many standardization jobs were needed in a hurry because of the 
war to aid in the procurement of war material, it was necessary to 
speed up the process. American War Standards are printed in a 
special color and format. As these are intended primarily as emer- 



8 J. W. McNAIR Vol 43, No. 1 

gency standards, each will be reviewed after the war to determine 
whether it shall be : 



(J) reapproved and continued as an American Standard, 

(2} revised, if necessary, or, 

(3} dropped if it has outlived its usefulness. 



Before the war, the American Standards Association was sup- 
ported entirely by industry; during the war, the War Production 
Board has placed the American Standards Association under contract 
for the specific standardization projects. The work in connection 
with 16-mm standardization is being accomplished under this con- 
tract. It was begun following a formal request for it from the Armed 
Forces to the WPB. 

The American Standards Association today is generally recog- 
nized as the national standardization body for the country. Some 
of the member bodies are : 



Automobile Manufacturers Association 

National Electrical Manufacturers Association 

American Institute of Electrical Engineers 

American Institute of Steel Construction 

American Iron and Steel Institute 

American Petroleum Institute 

American Society of Mechanical Engineers 

American Society for Testing Materials 

Photographic Mfrs. Group (Ansco, Eastman Kodak Co.) 

Fire Protection Group (Associated Factory Mutual Fire Insurance Companies, 
Nat. Bd. of Fire Underwriters, Nat. Fire Protection Assn., Underwriters' Labora- 
tories) 



Nine departments or agencies of the Federal Government are also 
affiliated. The Society of Motion Picture Engineers is an associate 
member. The officers and a number of members of the Society have 
cooperated to the fullest possible extent in both the organization and 
work of the ASA Committee Z52 on Photography and Cinematog- 
raphy. A very large proportion of the members of the committee 
and its subcommittees are members of the Society. We certainly 
could not have expected to have had more wholehearted cooperation 
than we have received on this job. On the work on the 35-mm part 
of the job the Society is cooperating with the Research Council of the 



July, 1944 AMERICAN STANDARDS ASSOCIATION IN WAR 9 

^ 

Academy of Motion Picture Arts and Sciences in setting up the several 
subcommittees in this field. 

For those interested in the methods and accomplishments of in- 
dustrial standardization, a good over-all view can be obtained from 
the December, 1943, Silver Anniversary Number of Industrial 
Standardization, the monthly journal published, by the ASA. 



SOME FUNDAMENTAL CONSIDERATIONS IN MILITARY 
AMPLIFIER DESIGN* 



S. L. CHERTOK** 

The design of amplifier equipment for military use differs consider- 
ably from the design of amplifiers for the commercial market, both 
in the physical details of construction and in the quality of parts 
which must be used for trouble-free operation in the field. 

The designer of military amplifiers must always keep in mind the 
extreme conditions of vibration, shock, high humidity, extreme low- 
and high-ambient storage and operating temperatures, and of salt- 
and dust-laden atmospheres to which the amplifiers may be exposed. 
Designing an amplifier which will stand up under these conditions is 
obviously not the simple job of catalogue assembly which typifies the 
design of ordinary commercial equipment, which need withstand 
only relatively "kid-glove" usage, in temperate climates. 

Further, the amplifier designer must keep in mind that the using 
personnel may not always be carefully trained sound men. Con- 
sequently, equipment must be as simple and foolproof to operate as 
possible, so that the most untrained "GI" can use it if necessary. 
Also, the designer must always remember that eventually the equip- 
ment will need repair. He must make provision for quick and easy 
replacement of parts with other standard parts. There is not a 
service man around the corner nor is there a parts' jobber 2 miles 
down the street out in the South Pacific jungles. 

One thing the equipment designer can forget is eye appeal. Com- 
mercial streamlining and fancy chrome trim need not be allowed to 
compromise a good electrical design, and functional placement of 
controls. Plain "o.d." or Navy gray is the height of fashion. Sym- 
metrical placement of controls is frowned upon. Operators will 
make mistakes under pressure in the dark. Experience has shown 
that asymmetrically located controls will prevent many faux pas 
in operation. Likewise, controls must be far enough apart and large 



* Presented Apr. 19, 1944, at the Technical Conference in New York. 
** American Standards Association, New York. 



10 



MILITARY AMPLIFIER DESIGN 11 

enough, so that they can be operated with a gloved hand. It gets a 
bit chilly showing pictures in the open with the thermometer hovering 
around freezing. 

The mechanical design of typical military amplifiers is much more 
sturdy than that of their commercial equivalent. Heavier chassis 
stock and reinforcements to prevent flexing are used. Generous use 
is made of lock washers, stop nuts, and other means of securing parts 
to insure their holding together under vibration. 




Official U. S. Marine Corps Photo 

FIG. 1. Truck-mounted, portable 16-mm sound motion picture 
projectors, such as this, are used to show training and morale films 
by the U. S. Marine Corps. 

Now, you may question the need for all this, but typical examples 
of the use to which military motion picture amplifiers may be put 
are the mounting of a projector and a small gas-driven generator on 
jeeps or trucks which drive around from area to area showing training 
and entertainment films as necessary. A typical example of a Marine 
Corps unit of this type is shown in Fig. 1 . 

The Air Forces require that portable projectors be capable of con- 
tinuous transportation for periods as long as 14 hr by air. Unless 
equipment has been properly designed, one or two such trips will 
head it for the scrap heap. 



12 S. L. CHERTOK Vol 43, No. l 

Again, in transport by Army truck or other means, equipment 
is not handled too gently. Consequently, amplifiers may be packed 
in their carrying cases and may be required to withstand drops from 
as high as 18 in. on a concrete floor, such as may occur when a man 
stumbles. A dozen or so drops is plenty tough on an amplifier, or 
anything else for that matter. There are also gun-shock considera- 
tions to be taken into account, such as may be experienced by equip- 
ment carried aboard ship. Permanently installed equipment is 
mounted on shock mounts which help reduce the intensity shock. 
Portable equipment lying on the floor may be put out of operation 
unless it is properly designed. 

The finishes and materials used in military amplifiers must be 
capable of withstanding exposure to salt-laden atmospheres, and 
liberal use is customarily made of stainless steel, plated brass, and 
other corrosion-resistant materials. Equipment specifications may 
call for metallic materials to withstand severe salt-spray tests under 
a 20 per cent salt-spray solution at 130 F for periods ranging from 50 
to 200 hr. 

Quite often amplifier cases must be drip or splash proof. Where 
equipment must be capable of operating under these conditions, it 
means that parts such as volume controls, which protrude through 
the case, must have special gaskets to keep moisture from entering 
through the tiny clearance space between the shaft and the bearing. 
When splash-proof designs are called for, equipments must not leak 
water when exposed to a 1-in. stream of water under a head of 35 ft 
played directly on the equipment from a distance of 5 ft for a period of 
5 min. 

Materials which are susceptible to attack by fungi, or are delect- 
able morsels for tropical beetles, must be avoided. It is customary 
to spray completely assembled equipments with various fungicidal 
and insect-proof agents. The eating away of cotton wire insulation 
by tropical insects can be avoided by replacing with wire that has 
glass insulation. Fungi will also attack the paper or textile base cones 
of loud-speakers, and proper impregnants must be used for the 
speakers if they are to last a reasonable length of time. 

Raw edges of all laminated punchings must be sealed. Otherwise, 
the layers will soon separate under tropical conditions. So much for 
the general idea of what faces a military amplifier designer in his 
general choice of materials. 

As far as the design layout of parts is concerned, the layer-built, 



July, 1944 , MILITARY AMPLIFIER DESIGN 13 

point-to-point wiring construction of so many commercial ampli- 
fiers is distinctly passt. A layer-built amplifier may represent a lower 
initial investment than an amplifier properly designed for ease of 
service and replacement, but the final cost of such designs to the 
military services is prohibitive. It is not considered good design 
practice in military equipment to save the last Vs in. of hookup wire 
and lower the price when servicing of equipment is impaired. Equip- 
ment that cannot be serviced easily soon ends on the junk pile. 

Fig. 2 shows an underchassis view of a radio receiver which illus- 
trates good design as practiced today for the military and for the de- 




Bendix Radio Photo 

FIG. 2. Cleancut, easily serviceable design in electronic equipment, 
such as is shown here, is desired by the Armed Forces. 

manding commercial customer. This particular photograph is one of 
a commercial prototype of an equipment which, relatively unchanged, 
has been furnished to the military services in large numbers. 

Compare this equipment with the ordinary 16-mm projection am- 
plifier, layer built and crammed to save the last possible inch of 
space. Note how the capacitors and resistors are mounted on ter- 
minal boards with very short leads so that they will withstand vibra- 
tion. Note also how the terminal boards are mounted so that if any 
resistor or capacitor fails, it may be quickly and easily replaced, since 
the strips may be quickly unscrewed and turned flat for ease of 
servicing. 

Note how the use of shielding wire has been avoided through use of 



14 S. L. CHERTOK Vol 43, No. 1 

copper tubing, allowing quick replacement of leads if necessary and 
avoiding the insulation leakage troubles which may occur with the use 
of shielded wire in the field. Note that all the capacitors shown in 
this particular view are of the molded type. I will have more to say 
on that later. Note also that most of the wiring has been preassembled 
as a subassembly and can be soldered in place by a much lower caliber 
of personnel than is needed to do point-to-point wiring. All in all,' 
I think you will agree that this is a much better type of construction 
than layer building. 

The terminal strips in this equipment have the so-called "turret 
lug" terminals which have come into favor during this war. This 
type of terminal solders more quickly than conventional types, and 
it is possible to remove either of the 2 connections soldered to a ter- 
minal without disturbing the other. In addition, connections be- 
tween various parts on the strips may be run above or below, allowing 
great facility in wiring. 

This type of construction lends itself quite readily to inspection. 
It is the usual practice to have each inspector place a drop of colored 
glyptal on each connection as it is checked. Different colors of glyptal 
may be used on different shifts to help identify strips in case of trouble 
on the final assembly. The proportion of manufacturer's inspectors 
to line workers on equipment of this type is much higher than that to 
which you are probably accustomed. It is quite common to have 
one inspector check the work of every 3 or 4 assemblers in order to 
insure a quality product with few rejections on the acceptance line. 
Of course, these inspectors are supervised again by the government 
inspectors. Compare this with prewar commercial practice. 

Parts in military amplifiers fail most usually because of troubles 
caused by high humidity. Consequently, components must be of a 
type which will withstand severe humidity tests either on the part 
itself or on the assembled equipment. Some parts are capable of 
being hermetically sealed. Today, the military services are de- 
manding that such parts be furnished if possible. There are various 
means of accomplishing this, such as gaskets, solder seals to glass 
or porcelain, or metal-to-glass seals with special alloys. 

For example, ordinary paper capacitors furnished 'in commercial 
construction are of the tubular cardboard-covered type. Electrolyt- 
ics may come through in an aluminum can, not hermetically sealed. 
In the former case, trouble usually occurs when the wax-end seals 
crack open and moisture enters. In the latter case, not only is there 



July, 1944 



MILITARY AMPLIFIER DESIGN 



15 



breathing of moisture, but there is also drying out and consequent 
loss of capacitance. In modern military construction paper ca- 
pacitors are either of the oil-impregnated, molded type, not wax 
impregnated as are their civilian prototypes, or else are of the oil- 
impregnated, oil-filled, metal-cased type. Fig. 3 shows an ordi- 
nary commercial paper tubular capacitor and its metal-cased "bath- 
tub" equivalent. As a quick check as to whether or not capacitors 
are properly sealed, samples are placed alternately in baths of warm 
and cold water. If they are improperly sealed, the capacitors will 
either short circuit, or there will be a marked decrease in the insulation 
resistance. 




Solar Mfg. Photo 

FIG. 3. This photo shows an 0.5 tf, 600-v paper capacitor of the 
type used in ordinary commercial amplifiers, left, and a hermetically 
sealed, metal-cased capacitor of the same rating designed for military 
electronic equipment. 

-As far as the electrolytic capacitors are concerned, they are con- 
sidered a necessary evil to be avoided whenever possible. In some 
cases, of course, it is not possible to avoid their use. Then special 
electrolytics, properly designed to withstand the specified operating 
ambients, are used. But, as you know, electrolytics designed for 
low-temperature operation are not the best design for high-tempera- 
ture applications and vice versa. Since motion picture amplifiers 
are not ordinarily used at temperatures below freezing you may 
think high- temperature electrolytics would be all right; but it must 
be remembered that equipment may be stored in tin shacks on 
deserts or transported in ships' holds stacked next to steam pipes. 



1G S. L. CHERTOK Vol 43, No. 1 

No electrolytic that I know of will withstand a temperature of 185 F 
(85 C) for more than 100 hr without having to be put back on a forming 
rack. Forming racks are not found outside capacitor manufacturers' 
factories. 

It has been reported that there has been extensive trouble caused 
from high-temperature storage conditions in equipments that were 
not at all affected by storage temperatures as low as 65 below zero. 
Incidentally, such low storage temperatures mean certain failure for 
parts sealed with ordinary wax or impregnating compounds. This is 
another reminder that sealing and impregnation of parts must be in- 
tended for military service. 

Transformers are usually potted and of late are also hermetically 
sealed. Where direct current must pass through windings, it is 
considered good practice today to use acetate winding cores, acetate 
layer insulation, acetate interlayer insulation, and acetate cross-strip 
insulation. The reason for the popularity of this insulation is typi- 
fied by the comparative requirements of one large equipment manu- 
facturer on a certain humidity cycling test. Acetate insulated trans- 
formers are required to withstand 80 days of test before failure, while 
ordinary unpotted paper units of the type used in the cheaper com- 
mercial amplifiers are required to withstand only 4 days on this test. 
Potting the ordinary paper unit brings its life up to 90 days on the 
same test. When the acetate insulation and potting are combined, 
you have a tremendous improvement in service life. When equip- 
ment is hermetically sealed on top of that, you will agree that there 
need be no worry about transformer failures from electrolysis or 
humidity in the field. 

Resistors, both composition and wire-wound, used in military 
equipment must withstand severe thermal shock and salt water im- 
mersion cycling tests as a guarantee of a reasonable length of service 
life. Composition resistors furnished today in military equipment 
are almost all of the so-called insulated type having a molded insulation 
over the resistance element. This insulation is never relied upon as a 
permanent insulation as is done quite often in commercial practice. 
The military services recognize that because of certain manufacturing 
conditions, it is quite possible to have a conducting layer of the 
resistance element extend in about l /& in. from each end around the 
resistor circumference. 

Insulated resistors using a ceramic outer shell are dropping out of 
production. Vacuum wax impregnation and filling of the ends will 



July, 1944 MILITARY AMPLIFIER DESIGN 17 

not keep out moisture as the wax cracks open during sudden shifts 
in temperature, such as may be experienced in aircraft. 

The wire in military equipment is not the push-back or rubber- 
covered wire used in ordinary commercial construction. The pre- 
ferred type of wire has an inner insulation of either 2 overlapping 
tapes of cellulose acetate butyrate, or of a vinyl compound, or has an 
extruded vinyl insulation. The outer braid is usually a double braid 
of fiber glass. The wiring is usually made up in harnesses which are 
preassembled after thorough checking. The forms on which these 
cables are made quite often have colored lines running between the 
various pins, so that the most inexperienced operator can assemble 
the cabling with little trouble. 

Laminated switches of the home vacuum-cleaner type found in 
commercial construction do not stand up in service. Molded 
housing- type switches are preferred. 

Tube sockets of the gang type are also out for military purposes. 
Not only do they not lend themselves to the use of tube clamps 
which are a necessity to withstand vibration and shock, but they also 
form a perfect leakage path between tubes when moisture enters the 
phenolic strips. 

With regard to the choice of tubes, the military amplifier designer 
does not have at his command the large and almost endless choice 
with which he can play in civilian design. Equipment designed 
for the services must have all tubes, including the photo-tubes, 
chosen from the Joint Army-Navy Preferred List of Radio Electron 
Tubes. Exceptions to this list are allowed only in very special cases. 
To design equipment using tubes which must be specially selected 
is considered an unpardonable sin of the highest order. Equipment 
must be designed so that any tube with the proper type number will 
work when plugged into a socket, regardless of whether or not the last 
2 db of output is sacrificed. 

Incidentally, not only in the choice of tubes, but in the choice of 
all parts are the services insisting on the use of standard, commer- 
cially available parts. The problems of stocking a multiplicity of 
special parts have been such that it is very easy for a designer to get 
into the "doghouse" through using special parts. 

Regardless of the type of parts that is chosen, manufacturers of 
equipment for the Armed Forces must have very thorough incoming 
inspection, checking each individual part as received. Slip-ups and 
mix-ups do occur in parts manufacturers' factories, as well as in 



18 S. L. CHERTOK 

assembly. If equipment is to be gotten out on time with the least 
amount of trouble, thorough incoming inspection is necessary. 

In order to facilitate servicing equipment, each piece or part must 
be identified by being marked with a circuit element number or by 
color coding. In cases where it is not possible to mark circuit element 
references on parts, they are usually marked on the chassis or mount- 
ing strips immediately adjacent. Compare this with ordinary com- 
mercial practice, especially when you remember that the repair man 
of commercial equipment does not have on hand, mounted on the 
chassis cover, or in some other convenient spot, the clear circuit 
diagram which the military services insist upon. 

The details of design and construction which I have just dis- 
cussed are, of .course, much more thoroughly covered in the procure- 
ment specifications of the service or services concerned. All these 
specifications emphasize the one "must" feature required of military 
equipment it must work under all conditions in the field, and that is 
the most essential feature to be kept in mind by the designer of mili- 
tary amplifiers. 



REPORT OF SUBCOMMITTEE B ON 16-MM SOUND* 
J. A. MAURER** 

At the meeting of the War Committee on Photography and 
Cinematography-Z52 held on December 15, 1943, Subcommittee B 
was assigned the task of preparing specifications for 16-mm motion 
picture sound-test films. 

The first meeting of the Subcommittee was held at Nela Park, 
Cleveland, Ohio, on Thursday, January 13, 1944. This meeting 
discussed a set of tentative specifications which had previously 
been drawn up as part of a program initiated by the Board of Gover- 
nors of the Society of Motion Picture Engineers, at its meeting in 
the spring of 1943, for the production of a new set of SMPE 16-mm 
test films. As the result of discussion by the Subcommittee, a new 
set of draft specifications was prepared for the following films : 

(1) A Test Film for Determining Uniformity of Scanning-Beam 
Illumination (frequently referred to in the industry as a "snake 

track"). 

(2) A Multifrequency Test Film for Field Testing 16-Mm Sound 
Motion Picture Projectors. 

(3) A 3000-Cycle Flutter Test Film. 

(4) A Buzz-Track Test Film for Adjusting and Checking Scan- 
ning-Beam Location in 16-Mm Sound Projectors. 

(5) A Sound-Focusing Test Film. 

The second meeting of the Subcommittee was held on March 7, 
1944, at the Engineering Societies Building in New York City. The 
draft specifications resulting from the first meeting were reviewed and, 
after amendment, were referred by vote of the Subcommittee to the 
parent Committee, Z52, with a recommendation that they be approved 
as American War Standard Specifications. This meeting also 
drafted a specification for a sixth test film, a 400-Cycle Signal Level 

* Presented Apr. 19, 1944, at the Technical Conference in New York. 
** Chairman, Subcommittee B, ASA War Committee on Photography and 
Cinematography-Z52. 

19 



20 J. A. MAURER 

Test Film, intended to provide a primary standard of signal level, 
accurate within approximately l /% db. This specification was also 
referred to the parent Committee, Z52, for approval as an American 
War Standard. / 

At its meeting in Cleveland on January 11 and 12 Subcommittee 
D on 16-Mm Projection had referred to Subcommittee B the problem 
of standardization of the dimensions of 16-mm sound records and 
scanning area. The March 7th meeting of Subcommittee B reviewed 
the work on these standards which had been done previously by the 
Standards Committee of the Society of Motion Picture Engineers, 
and approved a drawing embodying the result of this work with the 
addition of a specification for the dimensions of the printed area. 

The third meeting of the Subcommittee was held at the Engineer- 
ing Societies Building in New York City on April 20. At this meet- 
ing the Subcommittee discussed the objections to the proposed speci- 
fications which had been brought up in the letter ballot by Committee 
Z52, and recommended a number of changes. The specifications 
in their resulting, and probably final, form were referred back to 
Committee Z52 at its meeting on April 22. 

Subcommittee B, therefore, has completed its initially assigned 
tasks. However, at the meeting of Subcommittee C on 16-Mm 
Laboratory Practice on April 21, this committee referred the problem 
of sound-qualification tests to Subcommittee B. Your Chairman 
has appointed a subgroup under the Chairmanship of Mr. Clyde 
R. Keith to prepare recommendations to meet the needs of Subcom- 
mittee C. This group will study the problems of cross-modulation, 
intermodulation, frequency response, and flutter testing for the control 
of 16-mm sound-track processing, and is expected to draw up specifi- 
cations for the production and use of a special test leader to be made 
in both 35-mm and 16-mm. The sound- test material contained in 
this leader, after reproduction by whatever sequence of processes is 
used in arriving at the 16-mm release print, should furnish a basis for 
accurate evaluation of the quality of the sound track on the final 
print. It is believed that this test leader will prove an extremely 
useful tool for all laboratories doing 16-mm work, as well as meeting 
the present need of the armed services. 



REPORT OF SUBCOMMITTEE C ON 16-MM LABORATORY 

PRACTICE* 



M. R. BOYER** 

Subcommittee C on 16-Mm Laboratory Practice has been setting up 
specifications for 16-mm motion picture release prints. As explained 
previously, these specifications are intended to be War Standards, but 
many of them will be applicable to peace-time laboratory practice. 

To date the Committee has reached agreement on the following 
items in 16-mm print specifications: 

(1) Materials Fine-grain raw stock is recommended. 

(2) Print treatment Prints shall be treated over the entire width 
of the emulsion surface to facilitate projection. 

(3) Methods of marking prints A standard of marking prints 
has been set up so that the location of titles, type of print, and 
emulsion position will always be noted in the same location. 

(4) Physical defects A separation of well-known defects into 
tolerable and intolerable classification has been made. 

(5) Splices A standard width has been established, and an allow- 
able number of splices per reel has been decided upon. 

(6) Residual hypo content A method of measuring residual 
hypo content of prints has been chosen, and the maximum allowable 
content decided upon. This will probably be changed when per- 
manent standards are set up, as the consensus of opinion was that 
the allowable hypo content could be greater for war prints than for 
library prints. 

(7) Density and gamma variations Limits of allowable density 
and gamma variations from print to print have been established. 

On the following points decision has not yet been reached : 

(1) Resolution specifications. 

(2) Distortion and signal-to-noise ratio This will probably be 

* Presented Apr. 19, 1944, at the Technical Conference in New York. 
** Chairman, Subcommittee C, ASA War Committee on Photography and 
Cinematography-Z52. 

21 



22 M. R. BOYER 

referred to Subcommittee B on Sound, as methods of test have not 
yet been agreed upon. 

(3) Measurement of printer slip. 

(4) Dimensions of 16-mm printer aperture for picture. 

(5) Leaders and trailers Up to the present time it has been the 
custom to use the standard Academy 35-mm leader. There is ap- 
parently no particular reason for this in 16 mm, and a standard 16- 
mm leader will be proposed, as well as a standard trailer on which 
measurements may be made for both sound and picture uniformity 
and quality. 

On completion we hope to have set up standards of sound and 
picture processing which any purchaser of 16-mm printing may use 
as a basis for writing laboratory contracts. 



REPORT OF SUBCOMMITTEE D ON 16-MM PROJECTION* 
A. G. ZIMMERMAN** 

It had been our intention to report the activities of Subcommittee 
D on 16-Mm Projection of ASA War Standards Committee-Z52 in 
detail. Although of great interest to the Committee proper, it might 
be repetitious to some of us; however, to the majority, it should be of 
great interest and concern to the Society. 

With the papers presented by Mr. J. W. McNair, 1 Secretary of the 
Z52 Committee, and Mr. S. L. Chertok 2 of the American Standards 
Association, Secretary of Subcommittee D, there is little left for us to 
say regarding our committee activities they have covered the sub- 
ject quite thoroughly. 

We believe credit is due the Society of Motion Picture Engineers, 
and particularly the Chairman of the Non-Theatrical Equipment 
Committee of approximately 4 years ago, Mr. John A. Maurer. 
Through Mr. Maurer 's efforts, the Non-Theatrical group did ac- 
complish some results in arriving at certain specifications for 16-mm 
projection equipment, which would be a marked improvement over 
the existing equipments. Unfortunately, the Chairman was not 
permitted any spare time in which to prepare the material which 
had been discussed at the meetings of the Non-Theatrical group so 
that no complete minutes or specifications were issued. Mr. Maurer 
compiled this material, supplementing it with some additional in- 
formation, and presented to Z52 D a preliminary specification em- 
bodying the most desirable changes in features which the Society 
has fostered as a Non-Theatrical group, abridged with some improve- 
ments. 

It has been stated that the smaller the committee the more rapidly 
they move. It has been said that this Committee was the exception 
that proved the rule, inasmuch as at our Rochester meeting we had 
52 individuals present for some of our meetings. In this case the 

* Presented Apr. 19, 1944, at the Technical Conference in New York. 
** Chairman, Subcommittee D, ASA War Committee on Photography and 
Cinematography-Z52. 

23 



24 A. G. ZIMMERMAN 

presence of the specification enabled us to move into the subject 
very rapidly in the Cleveland meeting; thus enabling the American 
Standards Association group to prepare Draft No. 2, which, when 
attacked in Rochester, proved to be such that Draft No. 3 was not 
too difficult of preparation. 

It is my privilege, as Chairman of Z52 D, to report at this time, 
despite the very strenuous requirements as indicated by the speakers 
immediately preceding me, that upon favorable action of the parent 
Committee Z52 on April 22, the specification will be submitted to the 
Joint Army and Navy Board in Washington for action in a pro- 
gram which will establish the specification as JAN. This will 
complete our preliminary work in specification preparation on the 
Class / Projector (incandescent lamp) . 

Class // Projector, which is primarily to be the same mechanism 
except for provision for an arc lamp, will be prepared as soon as 
sufficient information is available regarding some of the design 
problems involved, as well as the definite decisions regarding the light 
source. 

The screen problem has been referred to a subgroup, headed by 
Mr. A. L. Raven, which is to prepare such information as is available; 
whereupon a meeting of Subcommittee D will be called to discuss the 
situation and compile a specification, in conjunction with the Armed 
Forces. 

The test films for use in either designing or acceptance testing the 
Class / or Class // projectors mentioned above were assigned to this 
Subcommittee. Action taken by the Subcommittee is such that they 
too can be submitted to Z52 for their approval; whereupon War 
Standard Specifications can be issued for procurement for the Armed 
Forces. 

May I, as Chairman of Z52 Subcommittee D, take this opportunity 
to express my personal gratitude to those who, either as direct rep- 
resentatives on the committee, or as auxiliary aids in other depart- 
ments of the Society or branches of the armed service, have con- 
tributed to the program which enabled us to complete our obligations 
with dispatch. 

REFERENCES 

1 McNAiR, J. W.: "The Role of the American Standards Association in War 
Standardization," /. Soc. Mot. Pict. Eng., 43, 1 (July, 1944), p. 5. 

2 CHERTOK, S. L. : "Some Fundamen al Considerations in Military Amplifier 
Design," /. Soc. Mot. Pict. Eng., 43, 1 (July, 1944), p. 10. 



REPORT OF SUBCOMMITTEE G ON EXPOSURE METERS* 

i 
J. M. WHITTENTON** 



A proposed American War Standard Specification for Exposure 
Meters has been drawn up as a part of the standardization activities 
of the War Committee on Photography and Cinematography- 
Z52. The Z52 American War Standards Subcommittee G, under the 
Chairmanship of Mr. F. K. McCune, undertook this work at the 
request of Capt. Lloyd T. Goldsmith, Signal Corps, who is Chair- 
man of the Armed Forces Committee on Photography and Cinema- 
tography. 

The Armed Forces in the past have purchased exposure meters 
which, for the most part, have been of the commercial type, designed 
essentially for peace-time applications. Reports from the field have 
indicated that not all of these meters have successfully fulfilled the 
rigid requirements of the armed services in battle areas in all parts 
of the world. This fact made it imperative to consider the service 
requirements for exposure meters and to draw up a specification that 
would cover a standard type of meter which would be entirely ac- 
ceptable, from the standpoint of construction and performance, to all 
branches of the service. 

Such a specification has been drawn up by members of industry in 
cooperation with representatives of the armed services, and it is 
hoped that this specification will be approved as a joint Army-Navy 
specification and used first as a development specification, and ulti- 
mately as a basis for procurement of production units. 

The work of this Subcommittee began by deciding upon a method 
of light measurement and maximum sensitivity. It was decided that 
the new exposure meter should be of the general-purpose type de- 
signed to operate on the principle of reflected light, in order to be 
adapted to all types of military use. The maximum sensitivity de- 

* Presented Apr. 19, 1944, at the Technical Conference in New York. 
** Alternate Chairman, Subcommittee G, ASA War Committee on Photog- 
raphy and Cinematography -Z52. 

25 



26 J. M. WHITTENTON Vol 43, No. l 

sired for such a general-purpose instrument was defined as "an 
instrument whose pointer would deflect at least 0.010 in. for an 
exposure of f/11 with a shutter speed of 1 sec and a film speed num- 
ber of 100, when used by the reflected light method." This repre- 
sented less sensitivity than had been previously supplied by most 
manufacturers, but this change was felt fully justified, since it would 
enable them to make more sturdy devices which would be necessary 
to meet the performance specifications which were to follow. 

The over-all performance of the device was next considered. An 
exposure meter is essentially a sensitive microammeter used in com- 
bination with a light-sensitive cell of the barrier-layer type, equipped 
with a suitable light-restricting mechanism over the cell, and a cal- 
culator by which exposure can be determined. In view of this, it 
was felt that the basic mechanism should meet performance speci- 
fications similar to those which were set up recently for small panel- 
type indicating instruments. The American War Standard for 
Small Panel Instruments, C39.2-1944, was therefore used as a basis 
for making up this proposed American War Standard for Exposure 
Meters. 

In this proposed standard, careful consideration has been given to 
the mechanical construction and electrical performance. From the 
standpoint of mechanical construction, the case design must be dust- 
tight and moisture-proof, all component parts will be required to be 
adequately protected against rust and corrosion when subjected to all 
types of world climatic conditions, moving systems will be balanced 
within closer limits, and ready means of instrument adjustment will 
be required. The calculators will be designed to use standardized 
//stops, shutter times, and ASA exposure index speed numbers. 

One of the prime purposes of this proposed standard was to set up 
requirements which would ultimately result in exposure meters 
made by various manufacturers indicating more nearly the same 
exposure. To attain this, rigid limits of angle of acceptance, method 
of calibration, cell spectral sensitivity, and performance were set up. 

The angle of acceptance of light energy striking the light-sensitive 
cell surface was defined, in order to more definitely control the 
directional characteristics of the device. Essentially this means that 
some form of hood, barrier, or grid must be placed in front of the 
cell in such a manner that not less than 60 per cent of the luminous 
energy actuating the meter from a screen of uniform brightness shall 
come from an area included within a cone whose half-angle is 25 de- 



July, 1944 SUBCOMMITTEE G ON EXPOSURE METERS 



27 



grees. Definite test conditions have been set up to insure the con- 
formance of meters to this requirement. 

The meter and calculator combination on all makes of exposure 
meters will be designed to conform with the following law : 



B X S 



(1) 



where / 



//stop; 5 = brightness of a uniform brightness surface as described 
below in candles per sq ft; 5 = Exposure Index or ASA Speed Num- 
ber; and T = Shutter time in sec. 



The specific calibration methods used by the various manufacturers 
will not be specified; however, a uniform brightness screen for a 



VIOLET BLUE GREEN YELLOW OR 



RED 




3600 4000 4400 4800 5200 5600 6000 6400 6800 7200 
WAVE LENGTH OF LIGHT (ANGSTROM UNITS) 

FIG. 1. Color sensitivity of various types of 
sensitive materials and cell compared with the 
energy in daylight. 

transfer standard has been described in order to insure that all types 
of meters will conform to the above law for calibration. This uni- 
form brightness screen has been described in general as a good quality 
pot opal glass illuminated approximately uniformly by a light of 
equivalent color temperature of between 2680 K to 2820 K at level of 
100 to 250 candles per sq ft. 

The importance of controlling spectral sensitivity of the light- 
sensitive cell has been recognized. The response of a typical light 
cell to light covers a range of wavelengths greater than that of the 
human eye and less than that of panchromatic film, as may be seen 
by Fig. 1. After comparing the spectral response of light-sensitive 
cells available today, an envelope curve was agreed upon which 
will control this characteristic within adequate working limits. The 



28 



J. M. WHITTENTON 



Vol 43, No. 1 



curve for cell response, as shown in Fig. 1, falls approximately in the 
center of the allowable envelope as set up in the new specification. 

Performance tests, more rigid and more in detail than previously 
required, have been made a part of this specification and are listed 
in Table 1, with allowable limits for each test. 

In addition to the requirements of shock and vibration tests in- 
dicated above, an abuse test has been added to insure that the ex- 
posure meters passing the performance tests will be sturdy enough to 





FIG. 2. Abuse-testing mechanism for service-model 
photographic exposure meters. 

withstand the requirements of the services. The tests will be made 
in an abuse tester which has been standardized for this application. 
It consists essentially of a tumbling barrel about 15 in. in diameter (see 
Fig. 2) which will rotate at a speed of 60 rpm. Sample exposure 
meters will be placed in this barrel and will have to withstand the 
random shocks of unpredictable acceleration for a period of one 
minute without becoming inoperative. 

Three of the leading exposure meter manufacturers generously 
contributed their engineering test data and experience on exposure 
meter design in the making up of this proposed standard. It is felt 



July, 1944 SUBCOMMITTEE G ON EXPOSURE METERS 



29 



TABLE 1 

Description of Test 

Initial accuracy 

Response time 

Temperature influence ( =*= 10 C change) 

Heat effect at +55 C (131 F), 3 cycles 

Permanent change due to +55 C test 

Cold effect perm, error due to 35 C (31 F) expos. 

Humidity test of 6 hr at +55 C (131 F) at 95 per cent RH 

and 18 hr in reducing temp and 100 per cent RH, 2 

cycles 
Effect of vibration at from 500 to 2500 cycles per min at 

. 018 in. to . 020 in. amplitude for 2 hr 
Pivot friction as a result of vibration 
Effect of shock 50 G (50 times force of gravity), 10 

times, 3 directions 



Test Limit 
(Upper / Scale) 

Within Vi//stop 
3 sec max 

Ve//stop max change 
Vs//stop max change 
Va//stop max change 
1 /if /stop max change 



1 A //stop max change 

V//stop max change 
l /i//stop max 

V//stop max change 



this work will result in a specification that will cover the require- 
ments for and the performance of exposure meters which will ade- 
quately meet the needs of the Armed Forces and also others who use 
this type of device. This proposed American War Standard should 
also be of much assistance as a basis for other standards for exposure 
meters which may be required in the post-war period. 



A FILM FOR MEASURING PROJECTOR STEADINESS* 
M. G. TOWNSLEY** 



Summary. A film is described which has circular perforations in each frame 
which are punched after exposure and processing of the film. The perforations in 
each frame are located from the normal film perforation and from the edge of the film 
which is guided during projection. The modification of a standard Bell and Howell 
perforator for producing this film and a method for checking the accuracy of the 
finished film are described. 



Steadiness in a motion picture projector is the ability of the film 
moving mechanism to place successive frames of film in the aperture 
in such a manner as to cause the images in each successive frame to 
occupy the same position on the screen. Sixteen-mm projectors 
locate the film frames vertically from a perforation and laterally 
from the edge opposite the sound track. 

A film having an image in each frame located vertically from the 
same perforation as is used in the projector and laterally from the 
guided edge may be used to measure the steadiness of a projector, 
provided that the location of the image is performed with sufficient 
precision. This could be conveniently accomplished by perforating 
a pattern in each frame at the same time as the film perforation in 
the raw stock. There are, however, certain disadvantages in this 
method. In the first place, it is usual to perforate several frames at 
the same time when punching raw stock. This introduces possible 
systematic errors in the film perforation and makes it necessary that 
the multiple punches required to perforate the steadiness pattern 
each be accurately located witih respect to the corresponding film 
perforating punch. The possible systematic errors in perforation of 
the raw stock and possible variations in punch sizes make it desirable 
to produce the steadiness test pattern one frame at a time, locating 
always from the same side of the perforation as will be used in projec- 
tion and from the guided edge. 

* Presented Apr. 19, 1944, at the Technical Conference in New York. 
** Bell and Howell Company, Chicago, 111. 

30 



MEASURING PROJECTOR STEADINESS 



31 



'ROJECTOK Sit/ 
Ttst Fa 



'pOJfcCTOR SltA 

TEST FILM 



Complete elimination of the systematic errors requires that each 
steadiness test pattern be located in the projector from the same side 
of the same perforation as was used in perforating. 

It has been found that a suitable pattern for 
steadiness testing consists of a film of medium 
density in which are punched two Vie-in, diameter 
holes in each frame of film. One of these holes 
is on the frame line and the other is located ap- 
proximately in the center of the frame as shown 
in Fig. 1. 

To be certain that the steadiness test pattern 
is located from the same side of the same perfora- 
tion as was used to locate it when it was punched, 
it is necessary that the film be threaded in the 
projector in the proper relation. This is accom- 
plished by printing a suitable title to identify the 
proper threading position of the film. The title 
is printed in a slightly lighter density on a 
background of density approximately 0.3 so that 
the title itself is only a threading guide and is not 
present in sufficient contrast to interfere with 
steadiness test measurements. 

After printing and processing of the title, the 
perforation of the steadiness pattern is performed 
on a modified Bell and Howell perforator (Fig. 
2). The perforator is modified to feed one frame 
at a time, and a "die set" having pilot, punches, 
film guide, guide pins, and stripper plate is at- 
tached to the perforator ram. As the ram de- 
scends, the pilot enters the perforation first. 
The pilot fills the hole vertically, but not laterally. 
Spring edge guides locate the film against a fixed 
rail. The shuttle is set to feed the film ap- 
proximately 0.002 in. short of its proper location 
so that the tapered end of the pilot makes the 
final location always from the same side of the per- 
foration. Figs. 3 and 4 show close-ups of the die set. 

As the descent of the ram continues, the stripper plate closes to 
hold the film firmly while the punch completes its stroke and per- 
forates the film. 



FIG. 1. Holes 
punched in film 
for testing projec- 
tor steadiness. 



32 M. G. TOWNSLEY Vol 43, No. 1 

Various projectors locate the film differently in the gate. This 
makes the film of maximum value only for the projector which 
locates from the same perforation as is used to locate in perforating 
the steadiness pattern. In the Bell and Howell projector, the film is 
located from the perforation at the upper corner of the aperture. 
The present film is made to locate from this same perforation. If the 
film is used in any other projector, the inherent steadiness of the film 




FIG. 2. Bell and Howell film perforator modified to feed 
one frame at a time. 

will be no better than the combination of the errors of original perfora- 
tion and steadiness perforation will permit. 

As a part of the title which appears in each frame are lines which 
tie together the two perforations in each frame which were punched 
at the same time and the film perforation from which they were 
located. As seen on the screen, these are the center and lower steadi- 
ness perforations and the lower left corner film perforation. 

Current projector specifications call for steadiness tolerances of 
from 0.2 to 0.3 per cent of the picture width. Careful workmanship 



July, 1944 



MEASURING PROJECTOR STEADINESS 



33 



in preparation of the film results in film with an inherent unsteadiness 
of approximately 0.05 per cent of the picture width. 

Two different procedures have been used to measure the inherent 
unsteadiness of the film. During the original experimental work 
which led to the present film, a projector was fitted with a cut-away 
aperture plate which permitted the perforation which located the 
film in the aperture to be projected on the screen. The relative 
unsteadiness between this perforation and the steadiness perforation 
was measured to give a direct measurement of the unsteadiness. 




FIG. 3. 



Close-up of "die set" used to perforate steadiness 
test film. 



The current procedure is to measure the relative unsteadiness be- 
tween successive frames. This is done by making use of the perfora- 
tion on the frame line. The perforation on the lower frame line was 
located from a different film perforation one frame behind the film 
perforation which located the steadiness perforation in the center of 
the frame. A pair of mirrors on a standard is set up approximately 
18 in. in front of the projection lens as shown in Fig. 5. The mirrors 
are adjusted in the projection beam so that the center hole is reflected 
to the screen by one mirror and the lower hole is reflected to the 
screen by the other mirror. Tilting screws on the mirror mounts 
make it possible to shift the images so that they are immediately 
adjacent to each other. The relative movement of the two images 



34 M. G. TOWNSLEY Vol 43, No. 1 

during projection is measured directly as the inherent unsteadiness 
of the film. All film now produced is completely inspected in this 
manner. 

It is obvious that the second method also checks the film for un- 
even spacing of the film perforations so that film which meets the 
unsteadiness requirements when inspected in this manner may be 
used in any projector. 

It has been suggested that a printed spot be used instead of the 
perforated hole. This would have the obvious advantage that the 
tendency of the present holes to collect dust would be overcome. It 




FIG. 4. Die set mounted in Bell and Howell perforator. 

has been found that the possibility of emulsion shift during processing 
imposes such rigid processing conditions as to make the production 
of film of sufficient accuracy seem unprofitable. 

The film is used to measure projector unsteadiness by threading 
in the projector so as to project the guide title correctly and pro- 1 
jecting the steadiness perforation to a suitable size. If the steadiness 
perforation is projected to a diameter of 15 5 /s in., the unsteadiness may 
be scaled directly with a scale graduated in tenths of an inch, Vio in. 
being equal to an unsteadiness of 0.1 per cent of the picture width. 
The unsteadiness is measured as the maximum excursion of the test 
pattern during the specified unsteadiness period. 

It is obviously necessary that the projector be rigidly supported 



July, 1944 



MEASURING PROJECTOR STEADINESS 



35 



during the test. This may be checked by projecting the edge of the 
aperture with no film in the gate, and examining the image for 
movement. 




FIG. 5. Adjustable mirror setup to measure the relative unsteadi- 
ness between successive frames. 



boat tau 



FIG. 6. 



The author is indebted to Mr. L. T. Sachtleben for the suggestion 
that lines be added to the guide-title to identify the steadiness pattern 
punched from a common film perforation and the film perforation 
from which they were punched. 



36 M. G. TOWNSLEY 

Several years' experience with this steadiness test has shown it to 
be accurate, simple, and readily performed by comparatively un- 
skilled personnel. The test film is simply and easily prepared, 
accurate when produced by skillful personnel, and readily inspected 
for inherent accuracy. 

Use of the film in a short loop tends to cause excessive perforation 
wear and the unavoidable jump from the splice tends to confuse the 
measurement. For these reasons, it is not recommended that the 
film be used in lengths shorter than necessary to perform the com- 
plete test. A length of 25 ft may be made part of a multiple purpose 
test film, but at least 50 ft should be used when no other test is in- 
corporated in the same film. 



THE EFFECT OF LAMP FILAMENT POSITION ON PROJEC 
TION SCREEN BRIGHTNESS UNIFORMITY* 



M. G. TOWNSLEY** 

Summary. Data are given on the effect of filament shift and filament rota- 
tion on the screen brightness and brightness uniformity in a high-efficiency 16-mm 
projection optical system. The data show that the filament location and orientation are 
critical for maximum brightness and best uniformity. The precision illumination- 
testing projection equipment used in making these tests is described. 

In 16-mm projection it is desirable that the screen brightness be 
as uniform as possible, and that the total screen illumination be as 
high as possible. Important among the many factors which con- 
tribute to the screen brightness and the brightness uniformity are 
the condenser design, the projection lens design, and the location and 
size of the lamp filament. 

Mili and Cook 1 have shown that properly designed aspheric con- 
densers contribute materially to the screen brightness and screen 
uniformity. The commercial difficulty of fabricating aspheric con- 
densers has prevented their wide commercial use although some com- 
mercial 16-mm projectors are equipped with aspheric condensers. 

Comparatively few data are available on the effect of the filament 
position on the screen brightness and brightness uniformity. It is 
the purpose of this paper to present the results of studies made in the 
laboratories of the Bell and Ho well Company on the effect of the 
filament location. 

The filament alignment in a projection lamp is not under the con- 
trol of the user so that the conclusions drawn from the present in- 
vestigations will be an indication of the allowable filament location 
tolerance in the lamp base and lamp socket construction. 

The condenser system in a 16-mm projector images the filament at 
a point usually within the projection lens and passes substantially all 
of the light which emanates from the condenser through a rather 
sharply defined circle at the position of the aperture plate. The maxi- 



* Presented Apr. 19, 1944, at the Technical Conference in New York. 
** Bell and Howell Company, Chicago, 111. 



37 



38 M. G. TOWNSLEY Vol 43, No. 1 

mum condenser efficiency is obtained when the filament image ap- 
proximately fills the projection lens aperture, and the aperture il- 
lumination circle is as small as is possible with complete coverage of 
the aperture. It is also necessary that the maximum possible solid 
angle be subtended by the entrance pupil of the condenser. 

Lateral shifting of the filament shifts the image of the filament 
within the projection lens so that it no longer properly fills the projec- 
tion lens, resulting in loss of light and uneven illumination in the pro- 
jector aperture. 

All 16-mm projectors are equipped with a spherical reflector 
behind the projector lamp which forms an image of the lamp filament 
in the plane of the filament itself. This image returns a consider- 
able quantity of energy to the filament plane and results in addi- 
tional heating of the filament and higher filament efficiency. Lateral 
shifting of the filament causes this reflected image to shift in the 
opposite direction, decreasing the overlap of the filament and image, 
and lowering the filament efficiency. 

The first set of tests was conducted to determine the effect of shift- 
ing the filament laterally. A 750-w, 100-v, 25-hr lamp was used with 
a high-efficiency condenser and a 2-in. //1. 6 projection lens. The 
condenser used is equivalent to the most efficient condenser used by 
Bell and Howell in a commercial projector. The lamp was operated 
at its rated voltage throughout the testing procedure. 

The equipment used in performing these tests is the projection 
optical testing bench which was developed for the purpose of testing 
projection optical and illumination systems in this laboratory. The 
entire unit is mounted on a large optical bench and consists of a. 
lamp house, which is equipped with a precision socket adapted to take 
a large lamp mounting flange, a movable condenser holder, which 
will accept any condenser diameter and may be moved longitudinally 
to position the condenser at the proper relation to the lamp, and a. 
movable aperture plate and lens holder, which may be moved longi- 
tudinally with relation to the condenser mount and lamp housing. 
This complete unit forms a flexible projection optical system which 
may be set up to simulate the optical system used in any desired 
projector. 

The optical bench is equipped with a saturated iron constant 
voltage transformer which maintains the voltage output constant 
within 0.1 v for a line voltage fluctuation of several volts. This 
effectively maintains the constant voltage on the lamp which is essen- 






July, 1944 



LAMP FILAMENT POSITION 



39 



tial to proper testing. Various voltages for testing with lamps of 
differing design voltages may be obtained by feeding the output of 
the constant voltage transformer into a tapped auto-transformer 
from which any output voltage from 15 v to 130 v may be selected 
in steps of one volt. 

Voltmeter connections are made directly at the lamp socket so 
that the voltage supplied to the lamps may be read without the in- 
clusion of any line drop. Large flanged brass rings are provided into 




FIG. 1. 



Construction and arrangement of lamp testing equip- 
ment. 



which the lamp is soldered in a special positioning fixture which 
projects both face and edge views of the filament on a graduated 
screen so that the filament may be properly located with respect to 
the base laterally, vertically, rotationally, and longtiudinally along 
the optical axis. When the lamp is thus positioned, it is soldered 
into the brass flange and the entire lamp and flange assembly is then 
ready for transfer to the projector lamp house. The flange diameter 
is maintained to fit the lamp socket. The flange is provided with 
a pin which engages a slot in the lamp socket to hold the lamp in 
rotational alignment. With this arrangement, it is possible to 
position the lamp filament with respect to the projector optical axis 



40 



M. G. TOWNSLEY 



Vol 43, No. 1 



within a tolerance of == 0.005 in. and a rotational tolerance of ap- 
proximately one degree. 

For the purpose of this test, a special lamp socket was constructed 
having a lateral slide so that the lamp could be shifted laterally, the 
amount of shift being measured by a depth micrometer. The rota- 
tional adjustment of the lamp filament position was made by at- 
taching a protractor to the lamp, unsoldering the lamp in the ring, and 
rotating the lamp through the desired angle. 

Fig. 1 shows the general arrangement and construction of the 

lamp testing equipment de- 
scribed, and Fig. 2 shows the 
lamp base which was used for 
these tests. 

A standard 16-mm aperture 
was projected to a screen width 
of 18 in. Screen illumination 
readings were made with a 
Weston Model 603 photometer 
at 9 positions on the screen: 4 
corners, the center of each edge, 
and the center of the screen. The 
reference position was the posi- 
tion in which the lamp filament 
planes were parallel to the film 
gate and the center of the fila- 
ment was on a line perpendicular 
to the film gate and passing 
through the center of the aperture. 
Table la gives the illumination readings at the 9 chosen positions 
for the lamp on center, 0.020 off center, 0.040 off center, 0.060 off 
center, and 0.076 off center. Table Ib gives corresponding readings 
converted to per cent of the maximum reading on the screen. It will 
be observed that there is a progressive decrease in screen uniformity as 
the lamp is moved laterally. This is most clearly seen in Table Ib 
where the lowest corner reading decreases from 74.07 per cent for the 
center position to 55 per cent for the 0.060 off center position. There 
is an apparent gain in screen uniformity for the position where the 
filament is 0.076 off center, but this is offset by the fact that the 
maximum brightness on the screen has decreased from 270 ft-c to 230 
ft-c. It is not considered desirable that the screen illumination at 




FIG. 2. Lamp base used for testing 
projection optical and illumination 
systems. 



July, 1944 LAMP FILAMENT POSITION 41 

TABLE i 

(750-w, 100-v, Westinghouse 25-hr Lamp, 8C-1A Condenser. Operated at 100 v, 
2-in. f/1.6 Projection Lens, 18-in. Screen Image) 

la Ib 

Illumination Per cent of 

in Foot Candles Maximum Illumination 

L C R 

Lamp Centered 220 260 210 81.48 96.29 77.77 

225 270 225 83.33 100.00 83.33 

200 250 207 74.07 92.59 76.66 

0.020 Off Center 190 235 220 71.69 88.67 83.01 

185 265 235 69.81 100.00 88.67 

175 235 210 66.03 88.67 79.24 

0.040 Off Center 168 233 212 67.20 93.20 84.80 

178 250 220 71.20 100.00 88.00 

157 220 200 62.80 88.00 80.00 

0.060 Off Center 145 220 220 60.41 91.66 91.66 

148 240 235 61.66 100.00 97.91 

132 210 210 55.00 87.50 87.50 

0.076 Off Center 145 200 204 63.04 86.95 88.69 

155 225 230 67.39 97.82 100.00 

148 210 210 64.34 91.30 91.30 

any corner drops below approximately 70 per cent of the illumination 
at the center of the screen. On this basis, it appears that a lateral 
shift of 0.020 is more than can be tolerated with this condenser design. 

Photographs were made of the filament image at the various set- 
tings to show the filling of the projection lens by the filament image. 
Fig. 3 shows the progressive stages of lateral shift. At 0.040 the 
lateral shift has become sufficient so that the reflected image has 
shifted noticeably from behind the filament. At 0.060 the shift has 
become sufficient so that more than Va f the filament image is outside 
of the lens covering circle, while at a lateral shift of 0.076 only about 
*/2 of the filament is being utilized. 

The second set of tests was made to determine the effect of rotary 
motion of the filament about a vertical axis on the uniformity of 
screen illumination. The tests were made in the same way as the 
tests for lateral shift except that a 115-v lamp was used. The lamp 
was rotated about its vertical axis passing through the center of the 
filament. Measurements were made at the reference position with 
the filament plane parallel to the aperture plate and the filament 
rotated 10, 15, and 20 degrees. Table 2a shows the effect of the rota- 



42 



M. G. TOWNSLEY 



Vol 43, No. 1 




FIG. 3. Progressive stages of lateral shift of filament image. 




FIG. 4, Filament appearance when rotated from the reference position 
by successive steps. 






July, 1944 LAMP FILAMENT POSITION 43 

TABLE 2 

(750-w, 115-v, Westinghouse 25-hr Lamp, 8C-1A Condenser. Operated at 115 v, 
2-in. f/1.6 Projection Lens, 18-in. Screen Image) 

2a 2b 

Position of Lamp 

TLamp Centered 
5 Deg Rotation 
10 Deg Rotation 
15 Deg Rotation 
20 Deg Rotation 



tion on the screen illumination readings. Two effects are apparent 
from this table and Table 2b which shows the same values converted 
to percentage readings. The maximum screen brightness decreases 
as the filament is rotated from the reference position, and the screen 
uniformity becomes progressively poorer as the rotation increases. 

At the reference setting, the lowest corner brightness was 73.8 per 
cent of the center brightness, and the center brightness was 306 ft-c. 
Five degrees rotation causes a 2 per cent decrease in center brightness 
and a decrease from 73.8 per cent to 66.4 per cent in corner-to-center 
ratio. This effect becomes worse as the rotation is increased and it 
appears that approximately 5 degrees is the maximum allowable rota- 
tion of the filament plane from the best or reference position. The 
photographs of Fig. 4 show the filament appearance as it is rotated 
from the reference position by successive steps. These photographs 
.show graphically the reason for the decrease in screen illumination 
due to masking of the filament coils as the filament is rotated. The 
photographs do not clearly show the reason for the decrease in bright- 
ness at the center as compared to the brightness at one edge of the 



Illumination 
in Foot Candles 
L C R 


Per cent of 
Maximum Illumination 


231 


290 


256 


75.4 


94.7 


83.6 


257 


306 


260 


83.9 


100.0 


84.9 


226 


272 


231 


73.8 


88.8 


75.4 


200 


279 


265 


66.4 


92.6 


88.0 


220 


301 


274 


73.0 


100.0 


89.5 


200 


270 


245 


66.4 


89.7 


91.0 


190 


258 


270 


65.5 


88.9 


93.10 


201 


290 


282 


69.3 


100.0 


97.2 


184 


250 


253 


63.4 


87.2 


87.24 


178 


242 


260 


61.37 


83.44 


89.65 


192 


265 


290 


66.20 


91.37 


100.00 


170 


230 


253 


58.6 


79.31 


87.24 


186 


220 


256 


65.72 


77.73 


90.45 


200 


241 


283 


70.67 


85.15 


100.00 


170 


210 


243 


60.07 


74.20 


85.86 



44 M. G. TOWNSLEY 

screen. This is partially explained by the closer approach of one edge 
of the filament to the condenser and by the rotation of the reflected 
image in a direction opposite from the rotation of the filament, so 
that the filament image is formed in a progressively differing relation 
to the filament itself, thus resulting in a change in the efficiency of 
the reheating process. At no time does the maximum screen bright- 
ness reach the brightness of the center of the screen with the filament 
in the reference position. 

Although the data given here represent the results of tests on one 
lamp and condenser combination, they confirm and represent a 
great mass of similar tests made on other condenser and lamp com- 
binations. The present lamp and condenser combinations were 
selected as being representative of excellent commercial practice. 

From the data given, it is possible to make a tentative selection of 
lamp position tolerance for any given criterion of the screen bright- 
ness ratio and acceptable decrease from maximum possible screen 
brightness. It is apparent from the data that for an efficient con- 
densing system, the lamp filament position tolerance will be small. 

REFERENCE 

1 MILI, G., AND COOK, A. A. : "Condensers for 16-Mm Optical Systems," J. 
Soc. Mot. Pict. Eng., XXVI, 6 (June, 1936), p. 603. 



A METHOD FOR MEASURING THE STEADINESS OF 
MOTION PICTURE CAMERAS * 



M. G. TOWNSLEY** 

Summary. The unsteadiness of the film motion in a motion picture camera may 
be directly measured in terms of the maximum failure to return frames to identical 
register on successive passages of the film through the camera by photographing a 
ruled target during each of the successive passes, and inclining the target before the 
second passage of the film through the camera. The amount of tilt and the line width 
depend on the focal length of the lens being used and the resolving power of the film. 

Unsteadiness in a motion picture camera is the failure of the film 
moving mechanism to register every frame in identical relation to the 
locating perforation and the guided edge of the film. The present 
test depends on the high order of probability that, if the same film is 
run through the camera twice, there will be one frame where the maxi- 
mum out-of -register condition in one direction on one run will coin- 
cide with the maximum in the other direction on the other run. For 
the frame on which this condition occurs, the displacement of the 
two superimposed images is equal to the maximum unsteadiness of the 
film moving mechanism. 

The measurement is facilitated by the use of a special target con- 
sisting of a series of parallel horizontal lines crossed by a series of 
vertical lines. Tilting of the target slightly about an axis normal to 
its plane between the first and second exposures causes the two images 
to cross each other at an acute angle. Rings are drawn on the target 
at convenient radii from the center, and the line width and degree of 
tilt are chosen so that the two images will normally cross" in such a man- 
ner as to bring the dark line of one exposure to just fill the light space 
between the lines of the other exposure, at one of the rings. The 
magnification is so chosen that the ring spacing on the target sub- 
tends a known distance on the film. 

Fig. 1 shows the target pattern as developed in this laboratory. 
The width of the black lines is equal to the width of the white spaces 

* Presented Apr. 19, 1944, at the Technical Conference in New York. 
** Bell and Howell Company, Chicago. 111. 

45 



46 M. G. TOWNSLEY Vol 43, No. 1 

between lines. When the target is tilted 2 40', the crossing point, 
where the line from one exposure just fills the space from the second 
exposure, is at a radius of ! 3 /s in. 

With a line width co and a rotation 6 between exposures, the line 

just fills the space at a radius Ri = and again at R 2 = 



tan 6 tan 6 

If the target is placed at the focus of a collimator having a focal 
length L, and photographed with a lens having a focal length /, the 

line image will have a width co' = . 




FIG. 1. 



A vertical displacement of one of the inclined exposures by a dis- 
tance s' will result in a lateral shift of the crossover point A' = 



tan0* 

This corresponds to an apparent shift at the target A = ( ). 

tan 6\ I / 

The most convenient target design contains a series of concentric 

i j 

rings separated by a distance AI = - , where Aj corresponds 

/ tan 

to a unit displacement s( of the images at the film. For maximum 



July, 1944 STEADINESS OF MOTION PICTURE CAMERAS 47 

sensitivity, AI should be as large compared to s[ as convenient. With 
s f 1} A, and L fixed, / tan may be maintained constant by changing 
tan 6 to correspond to the focal length / of the lens used to make the 
test. In the actual instrument as used in this laboratory, the fol- 
lowing parameters were chosen arbitrarily : 

A! = 1.375 

si = 0.001 

L = 32 
whence I tan 6 = 0.023273 

We proceed now to the design of the target for a specific applica- 
tion. Certain primary data may be selected for convenience. In 
the case of a 16-mm camera, the usual lens is of 1-in. focal length. 
The maximum unsteadiness expected is approximately 0.004. A col- 
limator objective of 32-in. focal length is to be employed. The target 
is to be calibrated with rings separated by a distance corresponding 
to an unsteadiness of 0.001 per ring. We have 



A = 



/ tan e 

0.001 X 32 
/ tan 6 



We may obviously choose tan 6 to give any A desired. This gives 
values of 6 : 

2 40' for T /2-in. lens, tan 6 = 0.04658 

1 20' for 1-in. lens, tan 6 = 0.02328 

40' for 2-in. lens, tan 6 = 0.01164 

In the equipment as used, stops are provided to limit the tilt, and 
feeler gages for setting the stops for each lens focal length. 

The line width co is chosen to give good resolution on the film and to 
have a simple relation to 9 and A, let 

R 2 RI = 2 A 

2A 2w 
2A - 551 

co = A tan 

Fig. 2 shows the appearance of the target when double exposed by 
running the film through the camera twice with the target tilted 
through 2 40' between the first and second exposures. The cross- 
over point at which the 2 target images merge into a continuous band 
is seen to be quite sharply defined and in line with the fourth ring of 
the target. Vertical displacement of the 2 targets with respect to 
each other will obviously cause this crossover point to move laterally 



48 



M. G. TOWNSLEY Vol 43, No. 1 




FIG. 2. 



\ \ 4M11& 

II 






FIG. 3. 



July, 1944 STEADINESS OF MOTION PICTURE CAMERAS 



49 



in the double-exposed pattern. Several rings are provided so that a 
displacement of the crossover from one ring to the next corresponds 
to 0.001 unsteadiness. 

The effect of a displacement equal to the width of a line is shown in 
Fig. 3. The crossover point is now seen to be at the center of the pat- 
tern. \ 

Use of a lens of longer focal length than 1 in. decreases the sensi- 
tivity of the test by decreasing the magnification. When it is neces- 
sary to use a longer focus lens, the shortest feasible lens is used and 




FIG. 4. 



Equipment used to make tests for motion picture 
camera unsteadiness. 



the calibration scale is multiplied by the ratio of the focal length of 
the lens used to 1 in., or the angle of tilt is decreased to increase the 
sensitivity. 

Complete equipment for making the unsteadiness test is shown in 
Fig. 4. The target is mounted on the til table plate at the left of the 
figure. This plate is equipped with stops and an overcenter spring 
and lever to control the tilt. The camera is mounted on the adjust- 
able support at the right. Film is loaded into the camera and ex- 
posed with the target tilted clockwise. Without moving the camera, 
the film is rewound, rethreaded, and run through the camera again 



50 



M. G. TOWNSLEY 



with the target tilted counterclockwise. When large numbers of 
cameras are to be tested, each is fitted with an auxiliary base plate 
which enables it to be removed from the supporting bench and re- 
placed in identical alignment. 

If the camera being tested uses 
35-mm film, it is necessary in re- 
threading to be certain that the 
identical perforation is used as 
was used for framing the first 
time. Failure to do this will 
result in the 2 exposures being 
one or more perforations out of 
frame and the test useless. 

The film is projected at slow 
speed in a standard projector, 
or is examined a frame at a 
time in a still projector. The 
difference between the extreme 
positions of the crossover in any 
2 separate frames is the maxi- 
mum unsteadiness of the camera 
film moving mechanism under 
test. Fig. 5 shows a typical 
series of frames which show an 
unsteadiness of 0.0013. 

Horizontal unsteadiness is 
measured in the same way, 
from the same film, by measur- 
ing the excursion of the cross- 
over point in the vertical lines of 
the pattern. 

FlG 5 The basic method was sug- 

gested several years ago by 

Dr. E. K. Carver during a discussion on perforation standards, and 
the specific embodiment as presented here has been in use in this 
laboratory for several years. Publication is made desirable at this 
time because of the demand from many government agencies for 
steadiness tests on cameras being purchased and the incorporation 
of steadiness requirements in many government specifications. 




A NEW MOBILE RECORDING UNIT FOR STUDIO AND 
LOCATION WORK* 



JAMES L. FIELDS** 



Summary. The planning and construction of a new-type mobile film recording 
unit in use in Hollywood and by two branches of the Armed Forces are described. 

When the latest-type mobile recording unit built by the RCA Vic- 
tor Division of the Radio Corporation of America was in the design 
stage, the following thoughts were kept in mind : 

(1} The unit must provide comfortable working conditions. 

(2) The unit must be completely self-contained for studio or location work. 

(5) The equipment must be arranged for easy operation. 

(4) All equipment in the unit must be readily accessible for servicing and 
maintenance. 

(5) The unit must have a minimum of waste space. 

It was decided that the recording compartment of the unit would 
be of aisle-type construction that is, the unit was to be free from 
any bulkheads thus permitting the operator to move to any point in 
the unit without having to go out the front door and walk around to 
the back door. This feature was considered to have several advan- 
tages, some of which are : 

(2) It would permit greater flexibility in the arrangement of equipment and 
storage compartments. 

(2) It would simplify the maintenance problem. 

(5) It would make easier the handling of equipment normally stored in the 
truck but used on the set. 

(4) It would allow better ventilation of the unit. 

In order to reduce the amount of waste space and to keep the over- 
all length of the unit as short as possible, the driver's compartment 
was incorporated into the recording compartment. This made the 
entire unit into a single room. Fig. 1 shows the layout of the unit. 
It will be noted that the additional length usually required because of 

* Presented Oct. 20, 1943, at the Technical Conference in Hollywood. 
** RCA Victor Division of Radio Corporation of America, Hollywood. 

51 



52 



J. L. FIELDS 



Vol 43, No. l 



the radiator, engine, hood, and dashboard has been entirely elimi- 
nated. 

The body of the unit was built on an open-faced, cowl-type Stude- 








































-^^ 








pr 

I CABLE REEL 


STAGE CABLE. 
FUSE PANEL 
*B* VOLT SUPPL' 


~> 
( 


RECORDER 
SYSTEM 
STORAGE 




AMF 








POWER^ 
OUTLET ' 
COMP 




/ 


\ 


^ 






KAO 


<6 


11 




DECK 




/ 














\v 




"" ~1 




r 






















STEPWELL 






' 












FRONT DEO 























PRE. AMR 






















COMR 




\JL 


CHARGERS 
MOTOR GEN. 




STORAGE COMPARTM 
POWER STORAGE Bfi 


EN" 

TT: 


rs 
. 




STEPWELL 




UNDER I 
DECK / 





FIG. 1. Layout of mobile recording unit. 





1 



FIG. 2. RCA sound recording truck. 

baker truck chassis having a wheel base of 152 in. Dual tires are 
used on the rear wheels and a 2-speed rear axle provides extra power 
for tough locations. 

The hangover of the body past the rear axle was reduced 18 in. by 



July, 1944 NEW MOBILE RECORDING UNIT 



53 




FIG. 3. Interior of mobile sound recording unit. 




FIG. 4. Access to storage battery compartment is through 2 outside doors as 
well as from inside. 



54 



J. L. FIELDS 



Vol 43, No. 1 




FIG. 5. Power batteries are serviced 
through compartment doors at left. 
Motor generator set is shown at right. 




FIG. 6. Recording machine and re- 
movable flooring for servicing recorder 
and filament batteries. 



moving all of the foot control 
pedals and the steering mecha- 
nism forward 18 in. The angle 
of the steering column to the 
floor was also increased, which 
effectively reduced the hangover 
an additional 6 in. 

The over-all height of the re- 
cording unit was not limited to 
the height of baggage car doors 
because the trend in recent years 
has indicated that motion picture 
studios prefer to use a trunk-type 
channel for distant location work. 
The minimum headroom clear- 
ance of the unit is 6 ft. A 4-in. 
space between the ceiling and the 
roof is packed with insulating 
material. The interior of the 
unit is finished with grain filled, 
enameled plywood. 

In order to make the unit easy 
to get into and out of, step wells 
were provided at the front and 
rear doors. An over-all view of 
the unit is shown in Fig. 2. An 
interior view of the unit is shown 
in Fig. 3 . Note how the rear doors 
open the full width of the body. 

The center of gravity was 
lowered by building the storage 
battery compartments below floor 
level. To facilitate the changing of 
batteries, all storage battery com- 
partments are accessible from the 
outside of the truck. The opera- 
tion of these outside doors is 
shown in Fig. 4. All compart- 
ments are also accessible from 
the inside of the unit. 



July. 1944 



NEW MOBILE RECORDING UNIT 



55 



The power batteries for operating the motor generator set and the 
JB-voltage dynamotor are on the right side of the truck, and the fila- 
ment and recorder batteries are on the left side of the truck. The 
power batteries are serviced through doors which open on the inside 
of the unit, as shown in Fig. 5. A section of the floor under the re- 
cording machine table is readily removable for servicing the recorder 
and filament batteries, as shown in Fig. 6. All battery compart- 
ments have a minimum clearance of 18 in. over the top of the batter- 
ies, and are equipped with electric lights. In order to prevent bat- 




FIG. 7. 



Equipment storage compartments, and. film loading 
compartment over spare tube drawer. 



tery fumes from getting into the recording compartment, all inside 
doors are provided with seals. The battery compartments are ven- 
tilated through louvers which open to the outside. 

Equipment storage compartments are above the power bat- 
tery compartments along the right side of the truck. Fig. 7 shows 
these compartments open. A film loading compartment is shown di- 
rectly above the spare tube drawer. Additional storage space is pro- 
vided in the front crown of the roof section. 

The motor generator and the 5-voltage supply unit are mounted in 
readily accessible soundproof cabinets directly over the rear wheels. 



56 



J. L. FIELDS 



Vol 43, No. 1 




FIG. 8. S-voltage supply unit and cable 
reels. 




FIG, 9, Mixing panel in location setup 
position. 



These compartments, with the 
doors removed, are shown in 
Figs. 5 and 8. 

The cable reels shown in Fig. 
8 are located at the rear of the 
unit. The cable reels are pro- 
vided with brakes to prevent 
the cable from unreeling too 
rapidly when it is being pulled 
out. Cables which are used on 
the set are stored in the com- 
partment directly over the B- 
voltage supply unit, also shown 
in Fig. 8. Speech and power 
cable connections may be made 
at the rear or at the front of 
the truck. 

The amplifier equipment, the 
recording machine, and the power 
control panel are mounted on 
the left side of the unit, with 
the recording machine between 
the power control panel and the 
amplifier equipment. All ampli- 
fier and power controls may be 
readily reached by the recordist 
from a sitting position in front 
of the recording machine. 

A linoleum covered deck even 
with the bottom of the front 
windshield has been built across 
the front of the body. A sec- 
tion at the right end of the deck 
has been angled downward and 
may be used as a desk for the 
mixing panel when the unit is 
on location. Hood clamps are 
provided for holding the mixing 
panel in place. A bar-type stool 
fits into a floor socket immedi- 
ately in front of the sloping 



July, 1944 



NEW MOBILE RECORDING UNIT 



57 



portion of the deck, thus, for location work, the mixer has an unob- 
structed view. This location setup is shown in Fig. 9. 

Two compartments, which open from the front of the body, are 
built at each side of the truck under the deck. The left-hand com- 
partment has an outlet through which power is supplied to the camera. 
The right-hand compartment is used for holding microphone pream- 
plifiers. Short jumper cables from the preamplifiers to the mixing 
panel pass through a small trap door in the deck immediately in back 




FIG. 10. Power outlet shown at right, compart- 
ment for microphone preamplifiers at left. 

of the mixing panel. Such an arrangement makes it necessary to 
run only 2 cables from the recording unit to the set when on location, 
one power cable for the camera and one cable from the preamplifier 
to the microphone. Fig. 10 shows the unit set up for location. 

The audio circuit used is a conventional bridging "bus" type using 
electronic mixing, therefore, no further description of it will be given. 
The power circuit is also of the conventional manually operated type 
and requires no further description. 

Recording units of this type have been used in the production of 
motion pictures for the past 18 months and have given satisfactory 



58 J. L. FIELDS 

service in all respects. Also, 2 units of this type have been supplied 
to the United States Navy, and a third unit is now under construction 
for the United States Army Air Force. 

The author wishes to acknowledge the work done by Mr. James W. 
Bayless, who supervised the construction of the units, and wishes also 
to thank the many others for the good suggestions that were used in 
the planning of these units. 



NOTE ON THE EVALUATION OF PHOTOGRAPHIC SPEED 
FROM SENSITOMETRIC DATA*-f 

C. TUTTLE** 



Summary. A method of ascertaining the gradient speed of a photographic material 
without the use of special gradient measuring instruments is pointed out. The de- 
rived formula shows the relation which must exist between density and log exposure at 
the value of exposure which is the reciprocal of the speed. 

It has been demonstrated by Jones 1 that a reliable determination 
of the effective camera speed of a photographic negative material 
may be made by the following sensitometric procedure. The char- 
acteristic curve of the material is produced in the conventional man- 
ner (Fig. 1). Upon this curve is located a point, A, at which the 
slope of the tangent has a value that is a fractional part of a second 
gradient. This second gradient is the average gradient of that por- 
tion of the D-log E curve which is used in making the negative. In 
terms of the figure, the range employed is designated by A to C. 
The position of A is determined by the condition that the tangent 
of the angle a shall bear a certain relation to that of the angle b. 
The abscissa of A in log E units is the basis upon which the speed 
rating is made. 

It has recently been proposed as an American Standard 2 that the 
reciprocal of the exposure at A, in meter-candle-seconds, shall be the 
speed. Specific conditions as set up are that the log E distance from 
A to C shall be 1.5 and that the tangent of angle a shall be 0.3 times 
that of angle b. 

It is obvious that the direct method of evaluating photographic 
speed according to this criterion involves the measurement of 2 
gradient values a procedure that is perhaps not commonly practiced 
in laboratories doing sensitometric work. The author 3 at one time 
suggested designs for various instruments with which the desired 

* Communication No. 818 from the Kodak Research Laboratories; received 
Sept. 5, 1941. 

f Reprinted from J. Opt. Soc. Am., 31, 11 (Nov., 1941), pp. 709-12. 
** Kodak Research Laboratories, Eastman Kodak Company, Rochester, N. Y. 

59 



60 



C. TUTTLE 



Vol 43, No. 1 



data could be readily obtained. In that paper it was also pointed 
out how the whole complicated operation of analyzing a sensito- 
metric strip and computing relative gradients can be performed 
automatically with a photoelectric densitometer. 

The author realizes that the instruments suggested are special 
tools requiring some expenditure of time and money to produce. 
For this reason the comparatively simple suggestion of an accurate 
and not laborious mathematical method of analyzing conventional 
sensitometric data may prove useful. 




LOG E (METER- CANDLE - SECONDS) 

FIG. 1. Method of determination of gradient speed point. 



The condition for the establishment of the speed value stated 
algebraically is 

Glimit = 0.3 Gaverage (1) 

in which Gumit is theoretically the first derivative of the density -log 
E function and G av era g e is by the specified condition the density dif- 
ference between A and Cin Fig. 1 divided by 1.5. 

Actually, with typical negative emulsions, it is not necessary to 
find (jKmit, as the theoretical dD/d log E for this first derivative value 
is very closely approximated by the ratio of a finite density increment 
to a finite log E increment, even if the log E increment is as large as 
0.3. Thus, in place of G limit we can write (A-A/0.3), where A 



July, 1944 EVALUATION OF PHOTOGRAPHIC SPEED 61 

and D 2 are densities on the toe of the curve produced by 2 log exposures 
separated by 0.3. 

The gradient value so found would apply to a point on the char- 
acteristic curve midway between DI and D 2 . The density at this mid- 
point would be the average of DI and D 2 again an approximation, 
but a very close one, for the photographic characteristic curve. 

For the value of G ave rage may be written the equation 



in which D$ is a density produced by a log exposure 1.5 greater than 
that which produced the density midway between DI and D 2 . 
With these substitutions, Eq (1) may be rewritten : 



This simplifies to 

17.18Da - 16.1801 = S (5) 

One further approximation is allowable. Since DI and D 2 are always 
on the toe of the curve, and therefore both numerically small, the 
decimal part (0.18) of the coefficient on DI and D 2 may be dropped, 
so that an algebraic relation presenting no arithmetic difficulties is 
the result : 

170 2 - 160i = 03 (4) 

By the use of this equation sensitometric data, as usually obtained 
for the plotting of characteristic curves, may be used conveniently 
to establish the gradient speed value precisely and without recourse 
to any special gradient-measuring device. Take as an example the 
typical data for a negative material sensitometric strip shown in 
Table 1. Column 1 shows the step numbers, column 2, the actual 
log E values in meter-candle-seconds, and column 3, the step den- 
sities. Now, the values in column 3 obviously may be used to form 
a series of DI and D 2 values. For example, let step 21 be the first 
DI value; the corresponding D 2 value will be two 0.15 steps farther 
along in the table, which is step 19. Now, the steps 19 and 21 really 
determine the gradient at step 20; hence, the first DI and D 2 values 
are entered opposite step 20. Columns 6, 7, and 8 are self-explana- 
tory. The last column, D 3 , is taken from column 3, starting at the 
llth step, thus advancing D s , to a position ten 0.15 log E steps from 
the points midway between DI and D 2 . 



62 



C. TUTTLE 



Vol 43, No. 1 



A cursory examination of the last 2 columns reveals that they are 
approximately equal at step 19, and the log E value from which the 
speed is to be determined should be about 3.75. To accept this 
as the true value, or even to interpolate in the table to ascertain 
the value, would be placing more than necessary reliance upon 
the densitometric accuracy for two DI and D 2 values. It is 
better to follow the procedure shown in Fig. 2 and to plot 
the points in column 8 against those in column 9. It will be 



!2.0 



10 




O 1.0 3.6O WO 120 

D 9 ( FOR CURVE A) LOG E (mjcs) FOR CURVE 8 

FIG. 2. Gradient speed determination by plotting data 
derived from density reading. 

noted that these points rather definitely establish the position 
and slope of a straight line (A). A dotted line at 45 degrees is 
drawn to establish the location of the point at which \7D<r-\Di is 
equal to D 3 . In this particular case, the value happens to be exactly 
1.08 identical with the D% value for step 19. The log exposure for 
the gradient speed determination is 3.75, as previously estimated. 
In general to find the value of log E which applies to a particular 
value of D s , it is desirable to construct a short section of a second 
curve by plotting a few values of column 2 against values in column 
9. This has been done in B of Fig. 2. This short segment of a curve 
may always be considered a straight line. By interpolation on this 
curve the log E value may be readily found. 



July, 1944 EVALUATION OF PHOTOGRAPHIC SPEED 63 

To check the results of the formula, the gradient speed value of 
this particular sample was compared with that given by other methods 
of gradient speed determination. The numerical results of all the 
most precise methods proved to be in excellent agreement with that 
found here. 

The particular set of data given in Table 1 was the product of 
very careful sensitometric and densitometric technique. Moreover, 
the data apply to a normal kind of negative emulsion curve with a 
typical toe shape and a long straight-line portion. Such perfect 
correlation of speed values and such easily drawn curves as those of 
Fig. 2 are hardly to be expected in routine work. If the sensito- 
metric and densitometric work is less refined or if emulsions of less 
conventional characteristic shapes are encountered, disagreement 
will probably result. 

TABLE i 

Sensitometric Data and Computed Values 



Step 


Log E 


D 


Di Do 


16Di 17D 2 


17Dj-16Di Di 


21 


3.45 


0.10 






0.83 


20 


3.60 


0.11 


0.1Q 0.13 


1.60 2.21 


0.61 0.95 


19 


3.75 


0.13 


0.11 0.165 


1.76 2.80 


1.04 1.08 


18 


3.90 


0.165 


0.13 0.22 


2.08 3.74 


1.66 1.21 


17 


2.05 


0.22 


0.165 0.29 


2.64 4.93 


2.29 1.34 


16 


2.20 


0.29 


0.22 0.37 


3.52 6.29 


2.77 1.46 


15 


2.35 


0.37 








14 


2.50 


0.47 








13 


2.65 


0.59 








12 


2.80 


0.70 








11 


2.95 


0.83 








10 . 


1.10 


0.95 




* 




9 


1.25 


1.08 








8 


1.40 


1.21 






* 


7 


1.55 


1.34 








6 


1.70 


1.46 


*" " . 







To test the general usefulness of the formula, samples of negative 
emulsions covering the gamut of present commercial emulsion curve 
shapes were obtained. Sensitometric data were then collected for 
these samples by the group of these Laboratories that deals with 
routine testing. The data were then subjected to the formula for 
the determination of the log E s values. They were also treated by 
an older, thoroughly tested method involving the use of a transparent 
scale known and distributed as the "fractional gradient speed meter." 



64 C. TUTTLE Vol 43, No. 1 

This meter measures directly on a characteristic curve plotted from 
the data and gives, in the hands of experienced users, entirely con- 
sistent results. For a description of the method see the paper pre- 
viously cited. 3 

A comparison of log E s values found by the formula and by the 
gradient scale meter is given in Table 2, along with a general de- 
scription of the character of each curve and the value of gamma for 
each sample. The greatest error is 0.03 in log E which is about 7 per 
cent in speed approximately a quarter-camera-lens stop. 

TABLE 2 

Log E t Determined by Different Methods 

Log E, Log E, 

Sample Description -y (Formula) (Scale) 

A Long toe 0.45 3.41 3.38 

B Same material as A 1.15 3.25 3.28 

C Normal shape 0.8 3.75 3.75 

D Normal shape 0.5 3.43 3.43 

E Short toe 1.3 3.23 5.26 



The sole advantage claimed for the use of the formula has been 
that the speed value may be determined from conventional sensito- 
metric data without resort to any auxiliary equipment. It might 
be mentioned, however, that the arithmetic involved would be 
materially shortened if the densitometer were calibrated to read 
16D and 17D directly. If it is desired to elaborate further on an 
instrument for use with the formula it would be possible to incor- 
porate a simple computer to subtract l6Di from \7Di. 

The accuracy and reliability of any method of speed evaluation 
are influenced by the following uncertainties: 

(1) The photometric inaccuracies of densitometry. 

(2) The unevenness of emulsion coating, particularly in that 
portion of the sensitometric strip which bears the low-density image. 

(3) The inequalities of sensitometric strip processing. 

(4) The uncertainty that a representative sample is taken from 
the emulsion batch. 

(5) The errors in sensitometric exposure caused by fluctuating 
lamp intensity. 

All of these uncertainties are decreased by taking multiple samples 
and by averaging the results. 
In cases where the importance of the results justifies multiple 



July, 1944 EVALUATION OF PHOTOGRAPHIC SPEED 65 

sampling, there are some interesting possibilities in the application 
of the formula to obtaining the gradient speed value directly. This 
formula may be written : 

17Z> 2 



Suppose that a sensitometer such as the Eastman lib instrument 
is altered slightly so that one-half of the strip, divided lengthwise, re- 
ceives the normal exposure, while the other half is given twice as 
much exposure. Each step of the processed strip will then consist of 
2 areas, the lighter of which represents D\ t while the darker represents 
Z) 2 . If 16 such strips are stacked in a pile with all steps in register, 
the densities will be additive, so that densitometer readings of the 
stack would give directly 16Z>i and 16D 2 .* Now, if a seventeenth 
sample is exposed on the sensitometer to give one side a twice-normal 
exposure and the other side a 45 times normal exposure, the 2 halves 
of the strip will represent Dz and D 3 , respectively. If this last strip 
is superimposed upon the stack of 16, the conditions required by the 
formula will be fulfilled. The reading of a stack of densities, as was 
pointed out by the author, 3 will very much diminish the probable 
error of the densitometry in the toe region and at the same time will 
minimize the other sources of error. 

It is of interest to mention that with such a stack of samples it is 
possible to assign the speed value approximately without the aid of 
even a densitometer. If the stack of strips is illuminated by a strong 
light, the lowest steps of the D 2 group are definitely more transparent 
than the adjacent area of the other group, but the gradient of this 
side of the strip is materially greater than the gradient of the other 
side, so that within a few steps it becomes definitely the darker side. 
There probably would never be a case in which the D 2 side, as judged 
by the unaided eye, would not change from the darker to the lighter 
in the increment of one step, so that it is safe to say that speed can 
be estimated to within 0.15 in log E, by this method. 

The more accurate method of comparison is, of course, to read a 
few steps of each half with a densitometer, and then, after plotting 
each set of densities against log E to determine the speed value from 

* The validity of the addition of densities by superposition has been questioned 
on the grounds that interreflections between layers would affect the numerical 
result. The procedure is justified in this case because one is interested only in 
the comparison of an equal number of layers at an equal density value. The 
surfaces concerned have nearly equal reflectances so tfce error if any is cancelled, 



66 C. TUTTLE 

the point of intersection of the 2 curves. Some modification of the 
conventional densitometer to enable it to read higher densities than 
usual would be found necessary. 

REFERENCES 

1 JONES, L. A.; "The Evaluation of Negative Film Speeds in Terms of Print 
Quality/' /. Frank. Inst., 227 (1939), p. 297; 227 (1939), p. 497. 

2 American Standards Association, Committee on Standardization in the Field 
of Photography, Subcommittee on Sensitivity to Radiant Energy. "Proposed 
American Standard: Specifications for determining photographic speeds of roll 
films, film packs, and miniature camera films," /. Opt. Soc. Am., 31 (1941), p. 87. 

3 TUTTLE, C. : "Methods and Instruments for the Determination of Photo- 
graphic Speeds by Measurement of Relative Characteristic Gradients," J. Opt. 
Soc. Am., 29 (1939), p. 267. 



TECHNICAL NEWS 

There appears in this issue of the JOURNAL a distinct innovation in the policies 
which have governed the Society's publications in the past. 

In accordance with an authorization passed by the Board of Governors on 
April 16, 1944, a section devoted to more or less current "Technical News" will 
appear in the JOURNAL about every 3 months. It is hoped that the various items 
of Technical News will not only be of interest in themselves to the members of the 
Society, but will also result in more detailed articles describing applications of the 
ideas to various phases of the production, distribution and presentation of motion 
pictures, and in allied fields. 

Technical advancements in the motion picture industry are often delayed in 
their publication to the point where their news value is lost. There are also 
occasions when technical advancements are made which are never published. 
It is the intent of this Committee, therefore, to be on the alert and obtain as much 
technical news as possible for publication in the JOURNAL as news items. In many 
instances it will be necessary that permission for publication be obtained. How- 
ever, since these items will not contain more than basic facts, it is felt that the 
Committee can serve a useful purpose to the Society membership in keeping them 
abreast of the times technically. 

The items* appearing in this section have been contributed by the members 
of the following Technical News Committee: 

A. C. BLANEY, Chairman 
RCA Victor Division 
Radio Corporation of America 
1016 North Sycamore St. 
Hollywood, Calif. 
Atlantic Coast Process Photography 

M. R. BOYER WILLIAM THOMAS 

E. I. du Pont de Nemours & Co. 851 Monterey Rd. 

350 Fifth Ave. Glendale, Calif. 

New York, N. Y. Sound 

Camera Equipment K. F. MORGAN 

H. W. REMERSHIED Electrical Research Products Dir. 

Bell & Howell Co. Western Electric Co. 

8339 Sunset Blvd. 6601 Romaine St. 

Hollywood, Calif. Los Angeles, Calif. 

Color Studio Lighting 

A. M. GUNDELFINGER C. W. HANDLE Y 

Cinecolor, Inc. National Carbon Co. 

2800 S. Olive Ave. 1960 West 84th St. 

Burbank, Calif. Los Angeles, Calif. 

* Submitted May 19, 1944. 

67 



68 TECHNICAL NEWS Vol 43, No. l 

Laboratory Practice Television 

EMERY HUSE H. R. LUBCKE 

Eastman Kodak Co. Don Lee Studios 

6706 Santa Monica Blvd. 3800 Mount Lee Dr. 

Hollywood, Calif. Hollywood, Calif. 

The Committee will welcome and consider items of current technical interest 
from any member of the Society. 



COLOR 

Technicolor Motion Picture Corporation. The following was 
taken from Technicolor's Annual Report : 

"Improvements in monopack procedure: Among the feature pictures produced 
in Technicolor was Lassie Comes Home distributed during 1943 by Metro-Gold- 
wyn-Mayer. The photography of this picture was largely exterior and from the 
Technicolor point of view was an experiment in monopack. The great beauty of 
the picture and its favorable reception at the box office speaks for the success of 
the experiment. But it only went part way because the monopack procedure will 
have to be improved so as to be satisfactory for the photography of interior studio 
scenes illuminated by artificial light as well as exterior scenes illuminated by day- 
light. Research work to this end has been undertaken by your company's research 
laboratory in cooperation with Eastman Kodak Company so that the Technicolor 
monopack process may gradually supersede the present Technicolor 3-strip 
process and thus eliminate the necessity of special Technicolor cameras." 

In addition to the foregoing, Thunderhead was produced in mono- 
pack and another major feature, Son of Lassie, is reported to be 
scheduled for early production. 

Producers Releasing Corporation. Plans are under way for the 
production of a feature-length picture by PRC making use of 16- 
mm Kodachrome for photography and the Cinecolor 35-mm 3- 
color process for release prints. Production on the picture is 
scheduled to start in June. Utilizing the above-mentioned mate- 
rial and process, several short subjects and a feature-length picture 
are already in production in Mexico City. 

LABORATORY PRACTICE 

Eastman Kodak Company. During May, 1944, the Eastman 
Kodak Company submitted to the motion picture industry in Holly- 
wood a new fine-grain variable-density sound recording film having 
the code No. 1373. This film is suitable only for variable-density 



July, 1944 TECHNICAL NEWS 69 

work and has excellent characteristics for this type of sound record- 
ing. The chief feature of this film is that it was made for develop- 
ment in a normal borax picture negative developer. 

Most variable-density sound films are of the positive-film type, that 
is, of high basic contrast. In order that they might be used success- 
fully at low values of gamma, it is necessary to use dilute borax-type 
solutions, which are often difficult to maintain. It is believed that a 
film of low basic contrast designed for development in a normal 
negative solution is a step in the direction of better sound negative 
control. 

Walt Disney Productions, Inc. A method recently developed 
at the Walt Disney Studios for edge numbering 16-mm Koda- 
chrome is now in use, and further improvements in it are under way. 
Among other things, it contains several unique features which 
probably will be disclosed in a paper to be presented to the Society. 

Cinecolor, Inc. In order to speed up work and facilitate produc- 
tion to accommodate increasing demands for 35-mm 3-color prints 
from 16-mm Kodachrome, Cinecolor, Inc., has plans under way 
for the expansion of its contract and optical printing facilities. 
Toward this end construction of a new Acme Dunn Optical Printer 
is nearing completion at the Acme Tool and Manufacturing Com- 
pany of Burbank, California. This printer will be installed shortly 
in the Cinecolor laboratory in Burbank. 

SOUND 

Warner Bros. Pictures, Inc. The latest production technique, 
which requires that motion picture sets simulate the structures that 
they are to represent with greater realism, has forced the Sound 
Department to construct a special microphone boom for small sets. 
The new boom is a little over 6 ft high, which is about half the usual 
size, and the boom arm may be extended to 14 ft. Its small size 
and relatively light weight, which is about 140 Ib, save considerable 
production time when working in constricted spaces. 

Work is nearing completion on a new reverberation chamber which 
is 25 ft sq and 10 ft high, and will have a reverberation time of 7 sec. 
The novel feature of this chamber lies in the arrangement of direc- 
tional microphones to control the amount of reverberation required. 

RKO Radio Pictures, Inc. In order to effect film saving and get 
recorded material back from the film laboratory more rapidly, 
direct-positive Class B recording is used on certain sound effects, 



70 TECHNICAL NEWS Vol 43, No. 1 

and where taps are recorded to be later added to dance routines. 
A further advantage is that clipping is avoided since no noise re- 
duction is necessary. When it is considered that as much as 10,000 
ft are often shot for one solo dance routine, the amount of film saved 
by not having prints can be appreciated. The direct positive is 
reproduced on an ordinary re-recording machine. 

The use of various kinds of microphones in the studio has made it 
necessary to have a universal microphone hanger, which in this 
case is a kind of fixture with 2 rapid-acting thumbscrews so that one 
type of microphone may be substituted for another quickly. 

In order that the film recordist may not leave a 3-position key in a 
nonrecord position during a take, a second pair of contacts has been 
added for the nonrecord positions which are energized by the starting 
system and cause a buzzer to operate continuously until the key is 
restored to its proper position. 

Walt Disney Productions, Inc. In recording of foreign versions 
of cartoons, a humming track is made of all choral groups so that 
this material may be used in certain foreign versions where singers 
for that particular language cannot be obtained. 

To create the effect of music or dialogue in underwater scenes, such 
as appeared in the picture Pinocchio, the sound track was reproduced 
on a machine from which the flywheel had been removed. The re- 
sultant speed variations created a warbling effect. This effect can 
also be greatly intensified by leaving the film gate open so that, in 
addition to the speed variation, the sound track tends to go in and out 
of focus. 

Republic Pictures Corporation. The automatic marker system 
at Republic Studios utilizes the existing camera power cables as a 
carrier system for the current supplied to the marker lamps at the 
camera and sound heads. A 2000-cycle signal generated by an 
oscillator in the sound truck energizes the marker lamps and a 
series resonant filter system is used to obtain minimum insertion 
loss at 2000 cycles and maximum loss at 60 cycles. 

Paramount Pictures, Inc. Paramount has instituted a practice 
of vacuum cleaning all sound negative after it has been recorded, 
and before it goes to the laboratory. This practice has resulted in 
an appreciable decrease in negative film noise. The vacuum 
cleaning equipment was developed at Paramount. 

A system has been developed wherein phase No. 2 of the stator 
between the distributor and the load is metered to indicate to the 



July, 1944 TECHNICAL NEWS 71 

recorder the number of cameras, etc., that are on the line. The 
meter is calibrated in terms of the machines on the line, and it oper- 
ates so effectively that the recorder can even tell when there is no 
film in the camera. 

STUDIO LIGHTING 

Recognizing the part motion pictures are playing in the war ef- 
fort, the WPB has issued priorities which are making possible the 
production of additional lighting equipment for motion picture studio 
use. 

There is a growing tendency in the use of light meters by Chief Set 
Electricians. The Chief Set Electrician, under the direction of the 
Director of Photography, is responsible for the placement and 
operation of all lighting equipment, and the light meter is proving a 
valuable means of control. 

(Ed. Note: Additional information concerning the items above, or the equip- 
ment and processes discussed, may be obtained by communicating with the gen- 
eral office of the Society, Hotel Pennsylvania, New York 1, N. Y.) 



SOCIETY ANNOUNCEMENTS 



ATLANTIC COAST SECTION 

The last monthly meeting of the Atlantic Coast Section until fall was planned 
to commemorate the anniversary of the first public showing of motion pictures. 
The program was divided into 3 parts briefly covering the past, present, and 
future of motion pictures. 

The past was represented by the exhibition of a 16-mm sound film produced 
several years ago by March of Time and supplied through the courtesy of the 
Museum of Modern Art. The film described some of the historical points of the 
industry with views from a number of well-known silent and sound pictures. 

The past was also represented by an exhibition of historical projector mecha- 
nisms arranged through the courtesy of the International Projector Corporation. 

To represent the present state of the motion picture industry talks were given 
by 2 representatives of the Army Pictorial Service on their experiences in motion 
picture photography on the African and Italian fronts. 

Major W. H. Rivers talked particularly about the supply problem and experi- 
ences in Africa dating from the first landing until the invasion of Italy. Major 
Arthur Ransom discussed his experiences landing on an Italian beachhead and 
photographing with the American Army at the front near Salerno. Major 
Ransom stressed the necessity for motion picture equipment capable of with- 
standing the rough treatment which is unavoidable in Army use. Two 16-mm 
films entitled Combat Bulletins were shown. 

To represent a phase for future development, a film supplied by General 
Electric was shown entitled Sight-Seeing at Home, describing the production and 
transmission of a television picture. 

Approximately 250 members and guests attended the meeting held in the 
Roof Garden of the Hotel Pennsylvania, May 24th. 

PACIFIC COAST SECTION 

R. B. Hood, special agent in charge of the Los Angeles office of the Federal 
Bureau of Investigation, addressed the Pacific Coast Section at its meeting held 
on June 6th. Mr. Hood told members and guests of the special problems which 
the Bureau faces during wartime, and described how motion pictures are used 
in the detection of crime. 

Following his remarks, Mr. Hood exhibited in the Paramount Studio Theater 
a selection of motion picture films taken from the Bureau library. These films 
were shown publicly for the first time. 

I ^^^^^^^^^^^^^ 

We regret to announce the death of Dr. Milo A. Durand, Active 
member of the Society, on May 15 t 1944, in New York. 
72 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

Vol43 AUGUST, 1944 No. 2 



CONTENTS 

PAGE 



Film in Television: 



Television Production as Viewed by a Motion Picture 
Producer W. COOPER 73 

Television Production as Viewed by a Radio Broad- 
caster W. C. MINER 79 

Duplication of Kodachrome Transparencies for Back- 
ground Projection E. K. MORGAN 93 

Kodachrome Transfer B. H. THOMPSON 95 

High- Efficiency Stereopticon Projector for Color Back- 
ground Shots F. EDOUART 97 

Present and Proposed Uses of Plastics in the Motion 
Picture Industry B. H. THOMPSON 106 

War Standards for Photographic Equipment Speed 
Military Instruction A. G. ZIMMERMAN 115 

American Motion Picture Standards 123 

The Requirements of Modern Projector Design 

R. H. CRICKS 129 

Current Literature 149 

Fifty-Sixth Semi- Annual Technical Conference 151 



(The Society is not responsible for statements of authors.) 

Contents of previous issues of the JOURNAL are indexed in the 
Industrial Arts Index available in public libraries. 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

HARRY SMITH, JR., EDITOR 
ARTHUR C. DOWNES, Chairman 

Board of Editors 

JOHN I. CRABTREB ALFRED N. GOLDSMITH EDWARD W. KELLOGG 
CLYDE R. KEITH ALAN M. GUNDELFINGER CHARLES W. HANDLBY 

ARTHUR C. HARDY 
Officers of the Society 
"President: HERBERT GRIFFIN, 

133 E. Santa Anita Ave., Burbank, Calif. 
"Past-President: EMERY HUSE, 

6706 Santa Monica Blvd., Hollywood, Calif. 
"Executive Vice-President: LOREN L. RYDER, 

5451 Marathon St., Hollywood, Calif. 
""Engineering Vice-President: DONALD E. HYNDMAN, 

350 Madison Ave., New York, N. Y. 
"Editorial Vice-President: ARTHUR C. DOWNES, 

Box 6087, Cleveland, Ohio. 

** Financial Vice-President: ARTHUR S. DICKINSON, 
28 W. 44th St., New York, N. Y. 

* Convention Vice-President: WILLIAM C. KUNZMANN, 

Box 6087, Cleveland, Ohio. 
"Secretary: E. ALLAN WILLIFORD, 

30 E. 42d St., New York, N. Y. 
"Treasurer: M. R. BOYER 

350 Fifth Ave., New York, N. Y. 

Governors 

**FRANK E. CARLSON, Nela Park, Cleveland, Ohio. 
*t CHARLES W. HANDLBY, 1960 W. 84th St., Los Angeles, Calif. 
**EDWARD M. HONAN, 6601 Romaine St., Hollywood, Calif. 
*JCLYDB R. KEITH, 195 Broadway, New York, N. Y. 
**JOHN A. MAURER, 117 E. 24th St., New York, N. Y. 
*HOLLIS W. MOYSE, 6656 Santa Monica Blvd., Hollywood, Calif. 
*WILLIAM A. MUELLER, 4000 W. Olive Ave., Burbank, Calif. 
*H. W. REMERSHIED, 716 N. La Brea St., Hollywood, Calif. 
**EARL I. SPONABLB, 460 W. 54th St., New York, N. Y. 

* JOSEPH H. SPRAY, 1277 E. 14th St., Brooklyn, N. Y. 
*REEVE O. STROCK, 111 Eighth Ave., New York, N. Y. 

**WALLACB V. WOLFE, 1016 N. Sycamore St., Hollywood, Calif. 

*Term expires December 31, 1944. 
**Term expires December 31, 1945. 
tChairman, Pacific Coast Section. 
tChairman, Atlantic Coast Section. 



Subscription to non-members, $8.00 per annum; to members, $5.00 per annum, included 
in their annual membership dues; single copies, $1.00. A discount on subscription or single 
copies.'of 15 per cent is allowed to accredited agencies. Order from the Society of Motion Picture 
Engineers, inc., Hotel Pennsylvania, New York 1, N. Y. 

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers, Inc. 

Publication Office, 20th & Northampton Sts., Easton, Pa. 

General and Editorial Office, Hotel Pennsylvania, New York 1, N. Y. 

Entered as second-class matter January 15, 1930, at the Post Office at Easton, 

Pa., under the Act of March 3, 1879. Copyrighted, 1944, by the Society of Motion 

Picture Engineers. Inc. 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

Vol 43 AUGUST, 1944 No. 2 



FILM IN TELEVISION 



Summary. The 2 following papers and subsequent discussion took place at a 
meeting of the Atlantic Coast Section of the Society in New York on March 22, 1944. 
The subject was limited to the use of film in television programs broadcast for recep- 
tion in homes, as an alternative to the production of programs of this type directly 
from live talent. Discussion was directed along 3 lines, i. e., the effect on technical 
phases of picture quality such as definition and focus, possibilities in artistic 
effects, and economic aspects. It was emphasized that the views expressed were 
personal opinions and did not necessarily represent the policies of any company or 
organization. Discussion section follows the second paper page 85. 



TELEVISION PRODUCTION AS VIEWED BY A MOTION 
PICTURE PRODUCER 



WYLLIS COOPER* 

I first want to qualify myself. I do not want to appear as a tele- 
vision expert. I have had a good deal of experience in radio, some 
experience in television, and considerable experience in motion 
pictures. I am going to talk to you for a few moments about the 
possible or probable use of motion picture film in television broad- 
casting. I want to emphasize again that what I am going to talk 
about are my own ideas and may not be shared by the people I work 
for. 

There is not any argument at all on the merits of motion picture 
film in television. The live type of television broadcasting may 
have its place and will have its place, and certainly there will be an 
enormous place for the use of film. The Wall Street Journal recently 
said, quoting some unknown Hollywood producer, that "Television 
is nothing more than a talking picture and talking pictures are our 
business." I have a slight quarrel with that statement. Certainly 
motion pictures are Hollywood's business, but the other half of the 

* National Broadcasting Company, New York. 



74 W. COOPER AND W. C. MINER Vol 43, No. 2 

statement, that' television is nothing more than a talking picture, is 
not adequate. Television is considerably more than a talking 
picture for a number of reasons, and we will try to go into those as we 
go along. 

In the development of any art medium, we must take into con- 
sideration the things that have gone before. Every development 
in any of the art mediums has been influenced by the work of the 
people who went before. Michael Angelo painted pictures. They 
were still pictures. They were fine in color and so forth. Somebody 
else discovered photography Niepce, Daguerre and Fox-Talbot, 
and the rest of them but each of the mediums as it was developed, 
had a considerable influence upon the development of the medium 
that followed. That is what is going to happen to television. Motion 
pictures came ahead of television. Motion pictures will definitely 
have some influence, great or small, upon the development of tele- 
vision, and television will undoubtedly have a great effect on what- 
ever follows it. 

In my opinion, the important point in the consideration of motion 
pictures in television is this : Television, to be acceptable apart from 
its novelty feature, must conform to certain standards of quality, the 
establishment of which the television industry had nothing at all to 
do with. The people who began radio had a great deal to do with 
the establishment of conventions and of standards. Although the 
radio industry will probably do the major portion of television broad- 
casting, they must conform to standards that have previously been 
set. 

Let us consider the standards of present-day theater films. The 
use of dissolves, fades, close-ups, and other cinematic devices is uni- 
versally understood. The technical quality of film is taken for 
granted by the audience. No matter how poor the story quality, 
or how bad the acting in a Hollywood film, the technical quality of the 
film is almost always above reproach. If there are deviations from 
the standard high quality of Hollywood films, lighting, photography, 
and so forth, they stick out pretty badly, and they are very obvious 
to everyone who sees them. It is equally obvious, then, if television 
is going to compete in the home with the motion picture and it is 
quite likely that to a limited degree it will it is necessary to accept 
the standards of present-day film production and to measure up to 
them. 

As another example of the conventions, those of editing entertain- 



Aug., 1944 FILM IN TELEVISION 75 

ment motion pictures are thoroughly understood by the audience 
probably because they are based on very sound psychological con- 
cepts. Any deviation, any use of makeshifts in editing, or in other 
phases of cinematics, becomes immediately apparent, and the audi- 
ence does not like it. For example, I mentioned the use of lighting. 
When you come in for a close-up from a medium shot, the lighting is 
always changed, of course, so that the 2 scenes will match. It is 
sometimes impractical to do that in television which is transmitted 
from a live pickup, because it is not always possible to use the same 
camera for a close-up and a wider angle shot. Usually there is not 
time to change the lighting, and an immediate change in the char- 
acter of the scene being photographed results. It takes attention 
away from the story and does something to the psychological reac- 
tions of the persons viewing it. 

Pudovkin, who is generally considered one of the best authorities 
on cinematics, says "the essence of the film is editing. Editing in 
time and space is vital to the production of a good entertainment 
picture, or, for that matter, of almost any other kind of picture." 
The use of film obviously gives you the opportunity to use all the 
technique of editing in time and space that you have in film for theater 
projection. Inserts, the use of stock shots of all types, matching 
close-ups, the general cinematic flow of the picture, are all functions 
of the film, and I use the term "film" in its generic sense and not an 
actual strip of celluloid with a silver emulsion. It is not always 
possible to make the best use of the various cinematic devices when 
one must depend upon instantaneous decisions in a studio to over- 
come the limitations of space, sets, characters, and so forth. 

There are many faults in present-day television. Many of them, 
of course, are due to equipment limitations and the war situation, but 
it goes without saying that these things will be licked within a few 
years following the end of the war. There are many other faults 
due to production. We hope that they, too, will be remedied. A 
film can be used for most television programs in the future. Under- 
stand, I say it can be used. Whether it will be used or not, I do not 
know. I do not think anybody knows at present. 

There are certain objections to the use of film. These can be 
broken down into 2 main objections: first, the cost of film pro- 
duction. A great many people think that to use film for television 
implies the use of film in the Hollywood manner, which certainly 
costs a lot of money. The equipment necessary for producing film 



76 W. COOPER AND W. C. MINER Vol 43, No. 2 

for television is another element that must be taken into considera- 
tion. 

The second principal objection is the question of time the time 
required for processing the film, and the lack of what some television 
people call immediacy, which is the quality of knowing that what you 
see is happening at the time you see it. 

In present-day television there is a great deal of talk about this 
immediacy. I, for one, feel that that /concept is considerably over- 
rated. Some people in television have gone so far as to use the word 
instantaneity. That is a philological handspring the like of which 
I have never seen or heard before. The fact that the singer is open- 
ing his mouth at the precise moment you see him on your home 
television set, is something I am afraid will not keep you awake nights. 
However, if you want to have him open his mouth and sing, and 
know that he is doing so at the exact moment you see him grimace as 
he reaches for a high one, it is all right with me. The flexibility that 
can be had by prescoring, and then having the singer mouth his 
lines with a pleasant smile, I think more than compensates for the 
stop-watch attitude you may have if you know he is doing it now. 

I want to talk for a moment about how to use film for television. 
As I said before, it is perfectly obvious that we cannot use the Holly- 
wood style, because the cost would be completely out of line. It 
would be impossible to spend the amount of money for television 
broadcasts which are fairly shortlived, like radio broadcasts as 
is spent in Hollywood. There must be a considerable change and 
some more economical way in approaching the subject of using film. 

We have to observe the analogy of television with radio. Tele- 
vision is coming into the home just as radio does. The programs will 
have to be of approximately the same length as radio programs, al- 
though nobody knows for certain what they will be. And in each 
case, whether we are using television for education, for entertainment 
or for news, we have these arbitrary standards already in existence. 
We cannot in any way foist inferior standards on a public that is 
conditioned by standards which have been a part of its life for many 
years. 

In radio, we do not find it necessary to set up a physical theater 
with a stage and sets and curtains and so forth in order to do a play. 
By a number of clever devices and by the use of conventions, we avoid 
expense and time. By now, in radio's second or third decade, people 
have become pretty well conditioned to the conventions of radio, 



Aug., 1944 FILM IN TELEVISION 77 

and they understand it as well as they do the conventions of the 
theatrical motion picture. We can do the same thing in television 
by the use of motion pictures. I mean, we can use shortcuts, and we 
can use a number of devices, but these must always be devices with 
which the audience is familiar and which they understand. 

Of course, we will have to borrow from Hollywood what we need. 
A great many things will have to be simplified, and owing to the tech- 
nical limitations of the medium, we will have to do a number of things 
that are not necessary in theater films. The point I am trying to 
make, somewhat laboriously, is that the perfection of a theatrical 
film is not a vital part of a film made for television. Just as we have 
shortcuts in radio when we do a play, there will also be the same short- 
cuts in a television film when we are making that film specifically for 
television. We will be able to use the over-all general technique of 
the cinema, but we will synthesize a new technique with the produc- 
tion of television films, and it will be definitely television technique. 

In the actual production of films for television, I want to point 
out what I think is a simple way. Starting with the script, it will 
have to be more carefully written than the average entertainment 
film script. We will borrow, as I said, from Hollywood, but we 
will have to keep in mind the fact that we are not making a picture 
which will be shown on an enormous screen to a large number of 
people at once. We will have to tell the story rather simply. For 
one reason, the television film will very likely be much shorter than 
even the average motion picture short. On the breakdown for pro- 
duction, it probably will be necessary to arrange the breakdown so 
that, as far as possible, the film can be shot in sequence. We cannot 
always do that, of course, but with some care and some insistance 
upon this as a vital part of television production, we can arrive at a 
situation in which much of each film will be shot in sequence. 

The actual production of the film presents some other difficulties. 
We will have to do a lot of cutting in the camera. We will have to 
keep down the number of takes as far as possible, because we will not 
have time to make numerous takes and, again, we are not seeking the 
perfection that we would have to have for large screen projection. 

The rushes should be made available as you continue shooting. 
You can make a rough cut as you go along. That may sound hard 
to do in view of present-day production methods in Hollywood and 
elsewhere, but I have a suggestion about that. If these pictures are 
made on 16-mm reversal film, it is quite possible to have on the set. 



78 W. COOPER AND W. C. MINER Vol 43, No. 2 

with the camera crew and the director the director, incidentally, 
should be a combination cutter and director a portable processing 
unit that can keep right along with the camera crew. As soon as 
the scene is shot, the magazine is handed to the man at the processing 
unit, and in a comparatively short length of time you have a positive 
print ready for projection. 

At the present time J am under the impression that it takes about 
15 min from the time you thread a developing machine until the film 
comes out at the other end, polished and ready to project. That 
time can be cut down appreciably, possibly not under existing condi- 
tions, but there are ways of speeding up the development of the 
reversal process. In that way, you have a rough cut of the film going 
right along with you. 

So far as the sound is concerned, you make that with a double sys- 
tem sound, process it at the same time, 'but the sound track is never 
printed on the picture print. It is cut along with the picture, rough 
cut as you are shooting, and by the end of your shooting schedule, you 
have a rough cut. With one or 2 hr more for the final cut, both of 
the sound track and the picture, you are ready for the actual broad- 
cast. It is perfectly simple to set up the projection arrangements so 
that you project from separate sound and picture films. It is 
going to be possible; it has been done and is perfectly simple to do. 

Special effects, if you want them, can be added. You can do pre- 
scoring to add sound effects or music at the same time you are shoot- 
ing the main part of the picture. It is a definitely specialized tech- 
nique with which no one has had much experience, of course, but it is 
perfectly simple to use andean be used. 

There is a great need, of course, for experimenting with this tech- 
nique. Nobody is going to be able to produce that kind of film day 
after tomorrow. The equipment for the most part is available, or 
could be "hay wired" together so that people could experiment with 
it as soon as they want to. The same technique can be applied to 
almost any kind of broadcasting. I am talking particularly about 
dramatic broadcasts, but musical programs can be done the same 
way. You prescore exactly the same as for Hollywood pictures, 
and then you avoid the appearance of tonsils and false teeth, and the 
pained expression when the singer tries to hit a high note. 

The stock shots, almost anything you want, can be intercut as long 
as your sound track runs straight through the way you want it to. 
You then have a film that looks as professional as a Hollywood enter- 



Aug., 1944 FILM IN TELEVISION 79 

tainment film, and is certainly up to the previously established 
standards. 

You can see that the cost of making a picture for television, if we 
use the method I have just proposed, need not be measured in Holly- 
wood figures. The equipment, of course, is expensive, but most tele- 
vision broadcasters have lights and cameras and other equipment 
already, and the total over-all cost to establish a modest film produc- 
tion setup for television of this type well, some equipment people 
might like to figure that one out. 

There is one other advantage of film for the picture that goes on the 
tube and that is, when it is photographed you have a record which you 
can keep and refer to, and cry over your failures. 

In network broadcasting, of course, the problem of supplying 
television broadcasts to distant stations is not of such importance, 
but certainly independent television broadcasters will make a great 
deal of use of film for this purpose. Any station with any trans- 
mitting equipment at all can use film, whether they can use the other 
type of pickup or not. 

I have tried to give you a rough outline of how film can be used 
in television. Experience and experiment will give the final answer, 
and the final answer will be the kind of picture you get on your home 
television receiver. 



TELEVISION PRODUCTION AS VIEWED BY A RADIO 
BROADCASTER 



WORTHINGTON C. MINER* 

I have been assured by your Chairman that this is strictly an off- 
the-record gathering in which honesty is to be the keynote. That 
seems to put it up to me to clarify one point right away. Your ad- 
vance publicity indicated that I was to discuss and presumably 
with some authority the problem of "Film in Television, as Viewed 
by a Radio Broadcaster." 

Just so that you may know how much credence to give to what- 
ever I say from here on, I want to state my qualifications as an 

* Columbia Broadcasting System, New York. 



80 W. COOPER AND W. C. MINER Vol 43, No. 2 

authority on this subject. My background is the theater. I have 
never been a radio broadcaster; I have had only the most cursory 
contact with pictures; and, like everyone else I have ever met, I 
know nothing whatever about television. So now I shall go right 
ahead and make an authoritative analysis of the entire problem for 
you. 

It has always seemed to me that in a discussion of this sort it is just 
as well for everyone to know as clearly as possible what we are all 
talking about. I therefore want to read a definition I wrote in pre- 
paring a report for television over 4 years ago : 

"Television is a new and inclusive art. It embraces many attributes of 
stage, screen, radio, and news reporting; yet it is none of these. It is not 
merely a derivative art, but an individual one, owing no more than a respectful 
gratitude to its ancestry. It possesses too many vital and unique character- 
istics of its own for it to adopt a servile allegiance to any paternal standard. 
Rather, it should allocate to itself the dignity of an independent standard, 
established in terms of its own peculiar, generic pattern. 

"It is the business of television to report the transient experience vividly 
and immediately, constantly alert to those unpredictable fragments of action 
and reaction that give life to the elusive moment. Television is the immediate 
truth presented in a pattern of deliberate selection." 

In other words, television is potentially the greatest reporting 
medium in existence. This is its supremely individual characteristic. 
It should be clear, however, that naming the characteristic of a 
medium is not defining what it shall do, but how it shall do it. Tem- 
porarily, television must exploit its most provocative characteristic. 
Both pictures and radio went through the same phase. 

So much for the definition of television. The next point which 
needs clarification is whether television can or should be limited to 
the production of entertainment. To the extent that pictures are 
produced for an audience to be assessed an admission fee, they must 
think in terms of show business, and that means entertainment. To 
the extent that radio, and likewise television, is produced for free 
distribution to the public, it must think in terms of public service. 
And within the scope of that concept entertainment takes a compara- 
tively secondary place. 

It may even be justifiable to question whether "entertainment" 
is not a biased limitation upon any discussion of television's potential. 
Consequently I am going to shift focus and analyze this problem 
as an answer to 2 basic questions : 



Aug., 1944 FILM IN TELEVISION 81 

First, should the backbone of a future television schedule for the 
home be produced on motion picture film ? 

And second, if it should, can it be done? 

I must confess that the answer to the first of these 2 questions is in 
the nature of a warning, rather than of a dictum. Just consider for 
a moment the basic problem of the psychological effect that a motion 
picture via television may have on the audience. Will it feel it is 
seeing something "canned," rather than the original? I do not pro- 
fess to know the public's response, but I can guess. And my guess is 
that temporarily, while the momentum of conditioning to motion 
pictures persists, the public will accept films of good quality without 
any great resentment. I will hazard a second guess, however, that 
there will be a growing uneasiness as the technical performance of 
live television pickup improves and live programs appear on any 
schedule bracketing film. I believe it will be a little like the differ- 
ence between seeing a football game and seeing a newsreel clip 
version of that game one week later. 

But the basic difficulty that faces the picture companies is the 
enormous breadth of scope in entertainment forms which they will 
suddenly be asked to cover. If it were possible to say that an 
entire television schedule of 10 hr a day could be made up of A pro- 
ductions from the top motion picture lots in Hollywood, it is possible 
that films might do a more excellent and polished job of production 
than television could ever do. But it is sheer folly to imagine that 
either 10 hr a day, or 5 hr a day, or even 2 hr a day can be solely de- 
voted to this type of entertainment. Television, simply because it 
must maintain a standard of public service, has an obligation to pro- 
duce in widely varied categories to a hungry public. It must pro- 
duce fully as widely as radio. 

Let us take a specific problem, the "Quiz." When Columbia was 
first considering the transmission of a regular television schedule, it 
debated seriously the advisability of attempting a quiz on television. 
A single fact, occurring at almost precisely the same moment, very 
nearly defeated the effort. (Remember that, because I am coming 
back to it.) Eventually a method of considerable flexibility was 
developed. It turned out to be a pretty good program, but some- 
thing very nearly stopped us from going ahead at all. That some- 
thing was the dismal and altogether dreary effort made by motion 
pictures to recreate the mood and quality of Information Please. 
I have not the foggiest notion whether or not a deal of intelligence 



82 W. COOPER AND W. C. MINER Vol 43, No. 2 

and imagination might evolve a satisfactory form of quiz on film, but 
I do know that it was most horribly mangled in that initial effort. 
All the years of experience behind motion pictures were not worth 
5 cents to the producers of that particular film. It was, in fact, 
a new form, and in meeting it they floundered like porpoises. It is 
unnecessary to analyze all the reasons for this. The fact remains that 
this is a glaring example of motion pictures falling down once they 
stepped outside the strict confines of show business, of entertainment 
for theater release. 

I do not know what a motion picture would do with Wings Over 
Jordan. I do not know what they would do with An Invitation to 
Learning. I do not know what they would do with The People's Plat- 
form. I only know one thing: They would have to throw away the 
book and start from scratch, and there is not one atom of proof that 
when the horses broke from the post, live pickup might not be half 
way round the track. But this type of argument can go on endlessly 
without being conclusive, for the simple reason that the best anyone 
can offer is an inspired guess, and a guess is a guess, no matter what 
adjective you put in front of it. 

So let us assume for a moment that pictures should by the best 
standards make a full 10 to 20 hr of television every day in the week. 
That brings us right down to cases with the simple question, "Can it 
be done?" Can one hour of television, whether it be entertainment 
or news, whether it be documentary or informal, whether it be re- 
ligious or social, can one hour o/ television be put on film cheaply 
enough to compete with the type of production which can be given 
with live pickup cameras? 

The first obligation is simply to take the established costs for the 
average A or B picture in Hollywood. Let us say that a good work- 
ing price for an A production is $600,000, for a B production, $300,000. 

The A productions run approximately an hour and a half. That is 
at a rate of $100,000 a quarter hour. Very obviously, so long as tele- 
vision is to be transmitted to the home free of charge, there is no ad- 
vertising rate in the world that can stand such an assessment. 

Now, let us assume that you are going out and make an hour's 
entertainment for something within reason for television distribu- 
tion. What is reason? I have heard that Voice in the Wind cost 
$40,000 to shoot and cost nearly that much again to add a new sound 
track. Forty thousand dollars is almost unreasonably low for a 
motion picture production, but it still is out of line with any reason- 



Aug., 1944 FILM IN TELEVISION 83 

able hourly rate for television. I have heard costs quoted on training 
films made by independent documentary producers of somewhere 
around $10,000 for 20 min. Nobody makes a great deal out of that, 
except in bulk. Yet $10,000 for 20 min is still $30,000 an hour, and 
that is still out of line with anything that television could afford. 
What, therefore, pictures must face is the fact that, because of a 
cold, hard economic equation, they will either have to lower the 
standard of film which they distribute to television, or make films 
for television at a staggering loss. Neither would appear particularly 
attractive. 

Let us look at it from another angle. A figure which I had given 
me the other day was that during the year 1943 Hollywood produced 
452 feature length pictures. Being overgenerous and assuming that 
these pictures ran an average of an hour and a half apiece, the total 
would be 678 hr. Presume that one network were to maintain a tele- 
vision schedule of 10 hr a day for one year I use 10 hr with no hidden 
implication, but merely because it is easy mathematics it would be 
putting out 3,650 hr of television, and if all of that were to be on 
film, Hollywood would have to multiply its plant 6 times before it 
could even take care of one television network. 

Now I have heard this problem bandied about and heard hundreds 
of different methods of cutting this pie so that it looks tastier for all 
concerned. The arguments are too long-winded to go into. So I 
am going to try, if possible, to tie this down to something so basic 
that this economic equation will suddenly become a vivid reality for 
you. I am going to talk about nothing but the cost of film itself. 

It takes 5400 ft of 35-mm film to make up one hour at present pro- 
jection speeds. Assume that a studio were to organize itself to shoot 
television entertainment at a ratio of 2 to one. This would mean 
that there would be 10,800 ft of negative used. At a cost of 6 cents 
per ft, that is $648. Suppose that sample prints were made up at 
a ratio of I 1 / 4 to one, and printed at 3 cents; the cost would be 
$202. The final print, 5400 ft, at 1.4 cents per ft, would be 
$75, a total of $925. For the air time to show this film on television, 
it would be necessary to employ 8 men at, let us say generously, 
$2 per hr; a total of $941 per hr. Now just remember this excludes 
any production cost talent, lights, scenery, promotion, distribu- 
tion, anything else; it is nothing but the cost of the film itself. 

Making the same eliminations for television, you would have to 
use, for the same hour on the air, possibly 20 men at the same $2 



84 W. COOPER AND W. C. MINER Vol 43, No. 2 

per hr, or a total of $40. That is a difference of approximately 
$900 per hr. Now, quite disregarding any other factor involved in 
the production, this would mean on a yearly basis at 10 hr per day 
you would be spending $3,285,000 merely for the luxury of using fihn. 
If you use 16-mm reversal, you can cut that cost by about 3, and say 
that it will cost you $1,000,000. It is these equations, and there are 
hundreds of them, which make many of us like myself seriously doubt 
that it is in any way realistic to consider film as the basic form for 
the backbone of a television schedule. 

I have taken up to this point an attitude that films cannot be used 
as the backbone of a television schedule. Now just in closing, I 
would like to mention some of the places where I think fihn can and 
will in all probability be used. For a number of years after the 
war, television stations are likely to grow up in scattered parts of the 
country, remote from the centers of talent, and temporarily linked 
to no major network stations. I think it is conceivable, therefore, 
that films may be used in this fashion : A show will be produced on 
television. There will be a receiver equipped with a 16-mm camera 
designed to make a visual and aural record of that program. As the 
program goes on the air, the camera will grind, and that fihn will be 
printed and distributed to these outlying stations at a rate which 
will make it feasible for them to contemplate a full television service 
without the staggering cost of producing the total number of hours 
within the confines of their own studios. 

I think there will be another important use for film, perhaps the 
most important and the most permanent. Both the broadcaster 
and the theater operator will eventually be receiving spot news a 
fire in Joplin, or a riot in Pittsburgh, or a parade in Butte, Montana. 
Many of these things will be unpredictable in time; many more will 
not be of sufficient importance to warrant allocation of full time for 
their showing. It would be ridiculous, for instance, to expect a 
New York exhibitor of a Betty Grable picture to stop the projectors 
20 min before the end and announce, "We now bring you a baby 
contest from Galveston." It would not even be feasible to do it if 
the television cameras happened to have caught the Hindenburg fire. 
What can happen is that a film recording of the remote and immediate 
event can be picked up, rapidly developed, and held for release either 
a minute, or an hour, or 10 hr later. 

I also believe that film may be used to enrich and give scope and 
change of locale internally to many television productions. Nobody 



Aug., 1944 FILM IN TELEVISION 85 

has yet measured how much pictorial effect can be gained from the 
limitations of a television studio. It is possible that television will 
develop a technique of many fewer setups and greater concentration 
than are normally practiced at the present time in pictures. In- 
evitably, however, there will be certain programs which will demand 
a sense of flexibility in time and space. When that is needed, I can 
see no reason why films should not be used for the purpose as parts of 
an otherwise live program. 

And finally, there will be a certain portion of every schedule almost 
certainly devoted to the release of film per se. I do not know the 
percentage, but I believe that it will be extremely selective; it will 
not be the backbone of a television schedule. 

In closing, I think there is one question which may have been 
growing in your minds as I have spoken. Granted that the argu- 
ments as I have presented them are valid, why should any motion 
picture person or company be interested in television ? As an an- 
swer, I would like to recall the brief statement I made at the opening : 
"Television is a new and inclusive art. It embraces many attributes 
of stage, screen, radio, and news reporting." 

There is, in addition, one simple fact which must not be forgotten. 
Television is a motion picture. It is adaptable not alone to home 
release, but can be used for theater release. There is no precedent 
to make me believe that the growth of television will supplant any 
previous medium such as pictures, radio, or newspapers. But I do 
know that television is all of these, and will intimately affect the 
conduct and the future in each of these fields. Every owner of a 
radio station, every owner of a picture theater, every owner of a 
daily paper, every publisher of a weekly pictorial is going to feel the 
effect of television. It cannot be ignored, and it cannot be held back. 
It is coming. And consequently it would appear to me that you 
motion picture people, looking at television, would be more realistic 
were you to ignore the problem of how to produce the best film version 
of a television program, and to ponder more and deeply on what a 
television program itself may be. Your future may depend on it. 



DISCUSSION 

Effect on Picture Quality 

MR. PALMER: I think it is quite obvious to anyone who has ever spent any 
length of time in a motion picture studio that the picture, as you see it on the 



86 W. COOPER AND W. C. MINER Vol 43, No. 2 

stage of the studio, is as far removed from what you see on the screen in the 
theater as it possibly can be. It seems to me that the only thing that the tele- 
vision broadcaster can put on the vido screen is a picture of what is happening 
in the studio and the way it looks. 

There are many things which happen to that picture in the processing which 
add immensely to its quality and to its perfection of detail, which you never 
saw at all in the studio. In the first place, the lighting in a studio has to be 
adapted to the limitations of the medium itself, the photographic emulsion, or 
the television camera, and the lighting in a studio is extremely "contrasty," in 
many cases, and very different from the way the film records it. What you see 
in the studio would not look at all good if you were to reproduce that same 
thing on the screen. In the processing of the film, however, many changes 
occur which add to its beauty and, you might say, to its audience acceptance. 

MR. MINER: I think there is not very much question about the validity of 
that statement, if people are judging television by its present performance. 
Certainly all of us have been suffering from a reasonably inferior performance 
up to now. We have reason to be extremely optimistic about what it will be 
in the future. But I think there will be perhaps some misapprehension about 
the quantity of things which television can presumably do, in order to achieve 
many of the effects which are now achieved on film in the laboratory and in de- 
veloping processes. 

In the first place, it is possible to exercise electronic control that can change 
the quality of high light and shadow. It is possible with proper lighting and 1 
have checked this and tested it it is possible even under present conditions to 
get a picture on television which can compare extremely well with the average 
type of light quality that you get on the average 16-mm film at the present time. 
I am not saying that I have seen anything on television up to the best of 35-mm, 
but there is an infinite opportunity to go much further than has been demon- 
strated at the moment, simply because there have been to date no absolutely 
efficient lights designed or built for television purposes, and the result is that a 
great many studios have had to operate with faulty equipment. However, 
having made one experiment under fairly limited conditions but with rather good 
equipment, I can assure you that you would be quite surprised at the number 
of gradations in the gray scale, and the quality of depth that appeared on the 
end of that television screen. 

It can be done, and furthermore, it can be electronically controlled by the 
control room engineer, who will become as adept in his profession as the average 
laboratory engineer is in the development of film. 

MR. COOPER: My experience has been that the quality of a picture on the 
television screen from even 16-mm is probably a little better than the average 
television shot. I say "average television shot" and I am also quite conscious, 
as Mr. Miner is, of the fact that not all the television shots you see are the best 
possible shots that can be made. 

MR. HYNDMAN: I think this problem resolves itself into one fundamental 
principle in current circumstances. Judgment can be based only by the currently 
available material in motion pictures and in the television field, whether it be 
equipment, processes, or film. 

Unless the television system is greatly improved, to the best of my knowledge 



Aug., 1944 FILM IN TELEVISION 87 

the problem is one of latitude and definition of the television system which is 
not now capable of giving high-quality tone reproduction or photographic quality. 
In motion picture production it is possible to have a latitude of 1 to 100 or, in 
exceptional cases, of 1 to 200 when photographing outdoor shots. This latitude 
can be recorded on the film because the film is capable of accepting it in terms 
of tone value and it is also possible to secure a high definition. The print from 
this negative does not have a latitude of the above-mentioned magnitude, but it 
is not necessary that it should because the screen upon which it is projected is 
not capable of accepting such a great latitude. A very high-quality motion 
picture screen when properly illuminated will give latitudes of from 1 to 30 to 
perhaps as high as 1 to 35. Most of us have become accustomed to this range 
of latitude and find it fully acceptable in a motion picture theater. 

From all the information that I have been able to gather, the television screen 
(the kinescope or receiving tube) is supposed to have a latitude of 1 to 20 at its 
very best, and yet, most engineers who have made an attempt to measure the 
latitude doubt that it is over 1 to 15. 

In these circumstances, it is impossible, therefore, to obtain a tone reproduc- 
tion on current television equipment that approaches what may be obtained 
from 35-mm motion picture film during projection, or even 16-mm motion picture 
film during projection. 

If we consider amateur motion picture film (the reversal type of 16-mm motion 
picture film), then the latitude is less than that of the films comprising the classic 
negative-positive process. It should be appreciated that 16-mm motion picture 
films obtained by reduction from 35-mm motion picture film have a latitude that 
is equivalent to the original 35-mm films so there should be practically no differ- 
ence in comparing them. There may be a slight loss in definition in the 16-mm 
reduction print, but at least from the standpoint of the picture, this is not notice- 
able to the average viewer. Furthermore, the latitude of the 16-mm screen and 
projection system can be conditioned to equal that of the 35-mm system provided 
sufficient illumination is available. An additional point is that the depth of focus 
obtainable on either 35-mm or 16-mm motion picture film is far beyond that 
obtainable with the current television system, especially when the images of all 
three are compared at equivalent magnification. 

The combination electrical and electronic optical system in television is not 
capable of giving the depth of focus comparable to that obtainable in motion 
pictures. This is due to the fact that the high sensitivity of the motion picture 
negative film permits photography with the lens working at low apertures, 
whereas the low sensitivity of the mosaic of the iconoscope will not permit working 
the lens at a low aperture to provide equivalent depth of focus. 

It is my belief that these factors definitely indicate that the motion picture 
equipment and the motion picture film do give an image of better definition 
and higher photographic qualities than is obtainable on the television system. 
The general public will eventually expect a photographic quality and definition 
in television comparable to that which is now available in motion pictures. 

MR. MINER: I think that there is a slight misconception. There are 2 factors 
involved in television. One is contrast range, and the other is a sensitivity within 
various gradations of the gray scale. It is certainly correct that the average 
performance in television at the moment has a contrast range of approximately 



88 W. COOPER AND W. C. MINER Vol 43, No. 2 

15 to 1. There have been laboratory experiments even before the war began 
which raised that to 30 to 1. There is every reason to believe and I cannot 
even quote you an exact figure that that will be considerably higher. I will 
not say how much higher, but it will be raised considerably. 

You have mentioned again the question of the depth of focus. That is with- 
out question a temporary problem in television. It is a factor involved in the 
size of the mosaic and the distance of the mosaic from the lens. As the smaller 
tubes are developed and a smaller mosaic is used which can be placed closer to 
the lens, there is no reason why the same depth of field cannot be achieved in 
television that can be achieved in any motion picture camera. The laws of optics 
apply identically, and it is only a question of the development of equipment 
which will supply approximately a duplicate of the size of, say, a 35-mm frame 
and place it as the mosaic within the camera tube itself. 

Naturally, it is true that we are talking here in terms of the future, but I am 
not discussing anything which is not a very eminently foreseeable future. 

MR. HYNDMAN: To avoid any misunderstanding, it should be emphasized 
that the fundamental problem is that a much greater sensitivity of the mosaic 
is desirable. This becomes very obvious if we will consider the mosaic as re- 
placing the negative motion picture film in a camera. When the mosaic has a 
sensitivity that is comparable to current normal speed motion picture negative 
film, then it will be possible to operate the television camera lens at a much lower 
aperture opening which will increase the depth of focus and also allow the tele- 
vision cameraman leeway in the adjustment of focus for definition. 

Unfortunately in some cases, it is general practice in the motion picture in- 
dustry to purposely expose motion picture negative film of high sensitivity at a 
wide aperture opening so as to have hi focus only the object of interest but, if 
it were desirable, the whole scene could be shot in needle-sharp focus by simply 
increasing the illumination of the scene and exposing at a much lower aperture, 
say, /5.6, or even /16. None of us doubt that with research and development 
progressing at its normal rate, the definition, depth of focus, and latitude of the 
television system will eventually be greatly improved over the present equip- 
ment and, when it is, it will open for itself numerous new fields to conquer. 

MR. MINER: Yes. The problem there of sensitivity is again in the future, 
but there is considerable reason to believe that there will be a tube in the market 
for television, at not too distant a date, which will equal or even surpass the 
sensitivity of any motion picture film on the market. I will not say there will 
not be motion picture film to compete with it eventually, but it is not outside 
of the knowledge of engineers at the moment. 

MR. OFFENHAUSER: I would like to supplement Mr. Hyndman's statement 
and say that all 16-mm film need not be considered amateur. I admit my preju- 
dice. 

MR. WAXMAN: From the viewpoint of a man who has a television set at home 
and sees these programs, I have always noticed that when we sit down to a play, 
the lighting, the definition, and everything else seem to be far superior than when 
they show films. 

The question also comes up about using 16-mm film. We all know that 
16-mm sound is limited to about 6000 cycles, and here we are trying to get high 
fidelity by adding FM to the sound which is supposed to go up to about 15,000 



Aug., 1944 FILM IN TELEVISION 89 

cycles. If we use 16-mm film with that 6000-cycle sound, we are not going to 
get very high fidelity. 

MR. OFFENHAUSER: What you get on it depends on how well you work it in. 

MR. WAXMAN: The best engineers in the motion picture industry say that 
it is 7000. They have admitted they cannot go much over 7000. 

MR. OFFENHAUSER: I can sell him all the film he wants with 15,000 cycles 
recorded on it at P/z cents a ft, provided he gives us a triple A priority or a 
directive. 

Possibilities in Artistic Effects 

MR. PALMER: It is very interesting to me to hear the blissful confidence that 
has been expressed here tonight, that you can produce in a television studio 
anything which will compare at all with a motion picture in entertainment value. 
I assume that people are going to still want to hear Fibber McGee and Molly 
and see them at the same time. Anybody who can produce in a television studio 
the sequence of events that happens in a Fibber McGee and Molly half-hour 
program has to have more movable equipment than I ever saw put together in 
one place. 

MR. MINER: I just happened to listen to Fibber McGee and Molly last night, 
and they never got out of the living room. I think we can get all around the 
living room. 

I do not know; I think it is perfectly all right that Casablanca was a success, 
but so was Oklahoma, and there is nothing to say necessarily that television is 
going to have to use a vast amount of scope and freedom in time and space in 
order to create good entertainment. There is no rule to say that because you 
keep within rigid formalities necessarily you cannot create good entertainment. 

There is also nothing to say that you cannot use entirely informalized scenery 
which may be sheerly indicative of location and create audience respect for that 
type of thing. It may make you put up a sign that says, "We are in the Sahara," 
and make them believe it. Just because pictures make them believe that they 
have to establish a set all over Burbank does not mean we have to do the same 
thing. 

MR. PALMER: Well, I cannot agree with that. In the very early days of 
motion pictures they used to paint the window curtains on the wall, and they 
got away with it then, but you will never get away with that sort of thing now, 
when people are used to seeing real window curtains. 

MR. COOPER: I agree with Mr. Miner that it is quite possible that a new 
technique may be developed in television whereby we may be able to indicate 
locations rather than actually show them. As a matter of fact, that technique 
has been used in motion pictures before, can be used again, and will be used again. 

I do not believe that you can do Fibber McGee and Molly in their present 
type of show merely by putting any kind of camera on them and having them 
walk around, going through their stuff, alternating between medium shots and 
close-ups. It is quite likely that a very different photographic technique will 
have to be evolved for entertainment programs. For example, one of the things 
that everyone must be thinking about is the daytime serial. That introduces a 
considerable problem, because every daytime serial has a definite setting. It is 
quite possible that in the production of that type of television broadcast there 



90 W. COOPER AND W. C. MINER Vol 43, No. 2 

will be a considerable use of rear-projection process shots, with a great deal of 
the action in close-ups. It is also possible that a great deal of the action to be 
taken will take place with off-stage voices and possibly stock shots of some 
kind to indicate the action. 

There is a good deal to be thought about in the development of a technique 
for television, either live or by motion pictures. We cannot arbitrarily photo- 
graph people going through a series of gag routines and expect to get a highly 
entertaining program. It is quite certain that for a television version of Bob 
Hope, or McGee, or what-have-you, we will have to evolve a completely new 
technique of our own which will partake partly of radio and partly of motion 
pictures. 

Economic Factors 

MR. SCHLANGER: With regard to the economics of the production of a picture, 
to make it economically possible to show a picture on television, I recall a ques- 
tion that I put to an exhibitor of motion pictures, a very successful single-run 
house, where the use of good short subjects would be a very welcome addition 
to the single feature. I said to him, "Why don't they make more good single 
features that is, short subjects that are condensed down to 8 to 10 min or 
12 min, and which are produced very economically because of the clever ideas 
in them the shortcuts that might be used by the art of motion picture pro- 
duction?" 

The answer was that if they got these good ideas, they would stretch them 
into a 5-reel feature, they need them so badly. 

Getting back to television, if you could produce a clever short by virtue of 
the art of the motion picture that has been developed and clever directing, you 
would not need stars, expensive stars, from Hollywood. Here is a chance to 
develop stars. So in the cost of your live talent, you could use all the short- 
cuts known to the motion picture art, and you could produce shorts for tele- 
vision which I believe would be economically in the right category. 

MR. PALMER: I think there is one thing that television might learn from the 
motion picture industry, and that is that they could use a lot of repeat action. 
When Walt Disney makes a duck waddle across the screen, he only has to make 
one waddle, and he can use that all the way across the screen. 

MR. FRANK: In Mr. Miner's talk, discussing the economic factors of tele- 
vison, he stated a lot of figures and quickly dismissed them by simply saying 
that it was too expensive. As I see it, in television there are 3 different types 
of programs that might be considered: One might be a sponsored program for 
pure entertainment purposes. One might be a sustaining program, and one 
might be an advertising program. Those of us who were privileged to hear the 
speech that Mr. Joyce of RCA made last week on the use of television as a selling 
tool were impressed about the possibilities of using it for advertising purposes. 
- Were you, Mr. Miner, dismissing these figures as being too expensive on the 
basis of any one of these 3 uses of television, or were you doing it simply on the 
basis of sustaining programs for entertaining purposes? 

MR. MINER: No, I dismissed them on the basis of any type of television, 
because when you have taken the cost of any film that I have ever heard of, and 



Aug., 1944 FILM IN TELEVISION 91 

you add line charges and other expenses involved in distribution to a network, 
the rental of the film is but a drop in the bucket compared to what some of the 
other costs are going to be. Consequently, it is not the total cost; I know no 
rate charges that will stand the cost of a good Hollywood A production, which 
is $100,000 a quarter hour. I do not think there is any advertiser who can 
possibly foot that bill it does not make much difference who he is. 

MR. PALMER: When Chesterfield cigarettes puts on a program in a Broadway 
theater, they fill it with people. Perhaps a production on film, after it is shown 
in television, could be distributed and exhibited in theaters throughout this 
country or the world, thus making it economically possible to spend larger 
amounts on the original production. 

MR. KEITH: I think perhaps another thing which might be added there is 
that the cost of the film is going to be divided up among a number of projections, 
assuming that you did not have to have instantaneous projection. Would that 
not be the case? 

MR. MINER: That certainly is the case, unless you are dealing with a network 
show which is presumably covering its major audience in one showing. Possibly 
you could get away with two. Nobody has really studied or experimented with 
that problem. There are those in England who made some checks which showed 
that audiences would not mind a repeat showing within a fairly reasonable 
length of time. But I think that when you have had 2 showings within a month, 
you have probably exhausted the network audience for any practical purposes 
commensurate with the cost which is involved. 

MR. COOPER: As far as this question of cost is concerned, I think we should 
pay particular attention to this: Television motion pictures do not need to be 
of the Hollywood variety. They do not have to be produced at Hollywood 
costs. They do not even have to be produced at the costs of ordinary com- 
mercial motion pictures that is, advertising pictures. 

One of the things that makes Hollywood films cost an awful lot of money is 
lack of adequate preparation. With a tight organization of television film pro- 
duction, and with enough attention paid at the beginning to the preparation for 
making the film, a lot of lost motion is going to be eliminated. 

Also, there are not going to be any of the tremendous write-offs that sometimes 
occur in Hollywood productions, because, as some of us may know, somewhere 
in the budget of $300,000 or $400,000 for an A picture is occasionally a $20,000, 
or $30,000, or $50,000, or $100,000 charge that belongs to the working title of 
the picture which was purchased a long time ago and is written off in the total 
cost of the production. 

I think that by careful attention to all the details of preliminary work in pro- 
ducing films for television, the over-all budget can be cut way down. It is also 
possible that in our conception of what advertisers will pay for television broad- 
casts, we may be a little wrong in comparisons. It is quite possible that when 
we get around to commercial television broadcasting we may find that the 
average cost of television broadcasting will be much more than the cost of the 
regular radio broadcast. However, by careful attention to details and holding 
things down to the minimum, I do not think it will be too far out of line to make 
them possible commercially. 

MR. SCHLANGER: One idea that may be of help is the narration idea, the splic- 



92 W. COOPER AND W. C. MINER 

ing in of narration to cut down the amount of pictorial stuff. During the narra- 
tion period a stock geometric pattern of harmless and pleasing type could be 
used, and the cut-in of the narration could reduce the production costs con- 
siderably. 



DUPLICATION OF KODACHROME TRANSPARENCIES 
FOR BACKGROUND PROJECTION* 

EARLE K. MORGAN** 



Summary. A process for duplicating Kodachrome transparencies for use in 
background projection is described. 

The use of still Kodachrome transparencies for background pro- 
jection is becoming an established process in making colored motion 
pictures. 

Natural color values and color correction are first in importance 
in making slides for projected backgrounds. The lack of control of 
these important factors in other methods led to the development of a 
duplicating process whereby color value, color correction, density, 
enlargement, and reduction are controllable. 

The following description outlines the method used to make the 
duplicate transparencies : 

The original color transparency is placed over one end of a light- 
proof tunnel (in this case the front bellows of a copy camera) with 
the copy lens at the other end. Two large daylight blue flash bulbs 
(approximately 60,000 lumens) in white reflectors are used. These 
are placed on either side of the copy camera and directed at a 
curved diffusing white surface 2 ft directly in front of the trans- 
parency to be copied. The film used is Daylight-Type Kodachrome 
and is exposed by open flash at stops as required by the size of du- 
plicates and density of the original. 

Color distortions in the original transparencies, or those intro- 
duced by the stereopticon projector, are corrected by the use of tinted 
filters. The use of these filters requires no change in exposure. 

In cases where lower contrast is desired, a neutral gray mask (a 
low gamma, black-and-white negative of the original transparency) 
is placed in contact with the original and the exposure made through 
both. 

* Presented Oct. 19/1943, at the Technical Conference in Hollywood. 
** Still Processing Dept., Paramount Pictures, Inc., Hollywood. 

93 



94 E. K. MORGAN 

Here is an example of density control : By decreasing the exposure 
at the time the duplicate is made it is possible to convert a daylight 
transparency into a night scene. 

The advantages of enlarging or reducing certain sections of a trans- 
parency are obvious. 

The duplicate transparencies are on an acetate base and are trans- 
ferred to glass before use in the projector. 

The original transparency is in no way altered and can be filed as a 
stock shot to be used for future pictures. 



KODACHROME TRANSFER* 



BARTON H. THOMPSON** 

Summary. This paper describes the method whereby a color image-carrying 
emulsion may be transferred from a plastic film base onto another medium without 
distortion of the image or bleeding of the color values. 

With the adoption of the high-intensity arc system used in stereop- 
ticon machines in the motion picture industry for background pro- 
jection purposes, the use of straight Kodachrome was rendered im- 
possible. It was also impractical to use Kodachrome cemented to a 
single piece of lantern-slide glass. As the demand for natural color 
still background transparency plates increased, an early solution to 
the problem was urgently needed. After an inspection of the plates 
exposed to the heat of the light system in the stereopticon, it was 
found that the principal difficulty was being encountered not in the 
breakdown of the Kodachrome emulsion, but in the disintegration of 
the acetate butyrate film base. The elimination of this plastic there- 
fore was imperative. After lengthy research, including tests and 
varying processes, the following procedure was adopted as a standard. 

Place a clean lantern-slide plate into position on a special plate 
holder. Next, place the Kodachrome previously cut to size, emulsion 
side down, upon the lantern slide and affix one edge of the Kodachrome 
to the plate holder with the use of transparent Scotch tape. Then 
fold the Kodachrome back, using the Scotch tape as a hinge and with 
the use of a medicine dropper place a bead of previously prepared 5 
per cent water solution gelatin on the lantern slide at the edge where 
the Kodachrome has been attached to the plate holder. Starting 
where cement has been applied, and with the use of either a squeegee 
or a roller, press the Kodachrome down upon the glass, maintaining 
a bead of cement at all times as the lamination is completed over the 
entire plate area. No great pressure is required in this procedure, 
but a steady drag of the squeegee or the roller is necessary. Remove 

* Presented Oct. 19, 1943, at the Technical Conference in Hollywood. 
** Research Engineer, Paramount Pictures, Inc., Hollywood. 

95 



96 B. H. THOMPSON Vol 43, No. 2 

the lantern-slide glass from the plate holder and proceed to the 
second step of the transfer. 

With the use of a weak solution of ammonia and water, dampen 
the gelatin backing of the Kodachrome and allow to stand for several 
minutes. Then with the use of a razor blade scrape all the gelatin 
backing from the plastic base. During this stage the film that is, 
the acetate butyrate film base may be damaged, but as this will 
be removed later it will not affect the finished article. After all 
gelatin has been removed, place the lantern slide in a petri dish par- 
tially filled with menthol cellusolve acetate, allow to stand for ap- 
proximately 4 min, remove, shake off the excess, and allow to stand 
for another 30 min. 

With the aid of a razor blade under one corner, lift off the swollen 
plastic. It will be found that the plastic has sufficient strength and 
will separate from the emulsion readily. If the plastic film is too 
tender, allow it to stand until strength has returned. This will 
range from 5 to 20 min. After the base has been removed, take a 
small piece of cotton, well saturated with menthol cellusolve acetate, 
and swab the surface of the Kodachrome emulsion to remove all ex- 
cess plastic. This might require 5 or 6 clean applications, or until the 
surface is perfectly smooth and glossy. The plate is then ready for 
use in the stereopticon. 

Another way to remove the acetate butyrate film base which was 
standard before the adoption of the menthol cellusolve acetate solvent, 
is by the use of acetone. The procedure up to the time of the im- 
mersion of the plate in menthol cellusolve acetate was the same, but 
at that point the plate was placed in a desiccator and allowed to stand 
for approximately 24 hr, or until the Kodachrome emulsion layer 
was dry. The plate was then removed from the desiccator and 
placed in a petri dish containing acetone, and with the use of a 
camel's hair brush the film base was dissolved by gentle agitation. 
Several applications of clean acetone were used to insure the complete 
removal of the acetate butyrate plastic. No further treatment to the 
plate was required for its use. 

Appreciation is hereby expressed to the Eastman Kodak Company 
and to Dr. Norwood L. Simmons of the Eastman Kodak Company for 
their assistance. 



HIGH-EFFICIENCY STEREOPTICON PROJECTOR FOR 
COLOR BACKGROUND SHOTS* 

FARCIOT EDOUART** 

Summary. The use of hand-colored slides in connection with transparency 
process production has long been practiced, but at best such slides are far from satis- 
factory. A solution to their limitations was to project and rephotograph natural 
color. Paramount Studios has designed and developed a stereopticon which projects 
natural color slides, and which incorporates such modern devices as a special relay- 
optical system, heat-absorbing shutter, and the latest-type projection light source. 
These features and other details of the transparency stereopticon are described in the 
following paper. 

Years prior to the advent of Motion Photography, when Edison 
invented his Kinetoscope, back in 1892, the old "Magic Lantern," 
with its oil lamp light source, was just the thing for an exciting 
evening's entertainment. And how well most of us can recall the 
various stages of development and advancement made through the 
more recent years, from the kind of lantern-slide pictures we enjoyed 
as kids, to the type of screen entertainment and artistry we now enjoy 
and demand. 

In keeping with the color motion picture production demands of 
today, Paramount has designed what we believe to be a most modern 
and up-to-date type of "magic lantern" or stereopticon projection 
equipment, incorporating a specially designed relay-optical system, 
with synchronizing heat-absorbing shutter, and powered with the 
latest type Mole-Richardson projection light source (Fig. 1). 

This stereopticon was developed to project natural color slides, 
in connection with the transparency process on color production, and 
constitutes a long step forward over the first stereopticon developed 
at Paramount along the middle part of 1932 for black-and-white 
transparencies. 

The use of hand-colored slides in connection with transparency 

* Presented Oct. 19, 1943, at the Technical Conference in Hollywood. 
** Director of Transparency Div., Special Photographic Dept., Paramount 
Pictures, Inc., Hollywood. 

97 



F. EDOUART 



Vol 43, No. 2 



process production has long been used, but at best this medium has 
been far from satisfactory for a number of reasons. First, the 
basic monochromatic values and density of the plates seldom permit 
the correct reproduction and richness of true color. There is the ever- 
present problem of coloring the slides correctly and evenly for en- 
largement to a screen picture of any size, a job requiring the most 







FIG. 1. Paramount transparency stereopticon, 
operating side showing adjustable plate holder and 
lens mount. 



meticulous skill, care and patience. Then there is the difficulty of 
securing stable nonfading color pigments and dyes that will stand the 
heat and intensity of the Super-Hi arc light. Added to these, there is 
the troublesome problem of securing heat-resisting, nonbreakable 
glass plates that will stand the terrific heat necessary for sufficient 
light to rephotograph in color. These are just some of the problems of 
using artificially colored plates. 



Aug., 1944 



STEREOPTICON PROJECTOR 



99 



Obviously the best solution to the problem was to project and 
rephotograph natural color. To do this required 3 major steps, each 
in itself a major necessary link in the accomplishment of the whole: 

(1) The duplication in quantity of correctly distorted, non- 
fading natural color prints 3 1 /* X 4 in. in size. In this connec- 
tion, it must be realized that the light source, condensers and 
optical system, slide glass, and the translucent projection screen 
used all act as a cumulative filter on the projected image. There- 




FIG. 2. Paramount transparency stereopticon cooling 
unit consisting of radiation units for water-cell and lamp 
water circulation. 



fore, the slide reproduction must be distorted in color to allow for 
this, so when finally projected the image should appear in the cor- 
rect color balance to the camera as originally intended. 

(2) The transferring of these duplications to a heat-resisting 
glass, water clear and free from bubbles or striae, and cemented in a 
manner to resist the most intense heat without peeling or separat- 
ing from the glass support and causing Newton-Ring effects during 
projection. 

(3) The designing of a unit to project the 3 1 /* X 4-in. image 
with sufficient light intensity to adequately rephotograph in color. 



100 F. EDOUART Vol 43, No. 2 

This required a light source and optical system producing the 
maximum efficiency, and required all the heat reducing and cooling 
elements we could employ, at the same time sacrificing a minimum 
amount of light and causing a minimum of color distortion. 



The light source provided for operation of the stereopticon con- 
sists of a Mole-Richardson lamp house designed to the Academy Re- 
search Council Process Projection specifications, and has specially 
designed condenser elements composed of a primary system consist- 
ing of a quartz plano-convex condenser exposed to the arc, and a 
pyrex double-convex condenser. These in turn are focused on a cir- 
culating water-cell system consisting of 2 plano-convex condensers of 
optical crown glass, which in turn are focused onto a field condenser 
system large enough to fill the 3 1 /* X 4-in. slide. 

The combination condenser water-cell is equipped for the intro- 
duction of filters such as heat absorbing, color distortion, or neutral 
density, mounted in a slide that drops into a set position covering the 
full light ray. They may be added or removed as desired, depending 
upon the amperage used, whether the slide being used is of nonbreak- 
ing glass, or whether the color ratio is required to be altered. The 
cell uses circulating deaerated distilled water to eliminate air bubbles 
from forming on the inside glass surfaces during operation, and is 
circulated by pump through a fan-cooled radiator (Fig. 2). The 
capacity of the cell circulation system is approximately 2 gal per min 
with enclosed liquid volume totaling approximately 1 /z gal. 

The circulation part of the equipment is a dual system, mounted 
in a case on the base of the stereopticon and connected by flexible 
transparent plastic tubing. This mounting, in addition to the cell 
circulating and cooling system, also contains the circulating water 
and cooling system for the lamp house, as the positive carbon- 
mounting unit in the Mole-Richardson lamp house is always kept 
down to hand-touch temperature, even while operating at 220 amp. 

The heat-absorbing glass used in the water-cell when occasion de- 
mands is the unusually effective glass developed by Dr. Tillyer, desig- 
nated as "Phosphate Heat- Absorbing Glass." 

Owing to the physical characteristics of this glass, it is most essential 
that it be utilized in such a manner that the entire area of the screen 
be subjected to heat of a relatively uniform level. Because of the 
comparatively high coefficient of thermal expansion, coupled with a 



Aug., 1944 STEREOPTICON PROJECTOR 101 

low degree of elasticity, lack of uniformity in heat absorption over 
the area of a piece of this glass is most likely to result in fracturing. 

Immediately adjacent to the outside of the water-cell, in the path 
of light between the cell and field condenser unit, is mounted a heat- 
absorbing shutter operating in the same manner as that found in 
35-mm background projection equipment, interrupting the light path, 
the shutter being operated in synchronism with the camera. Ex- 
perimental work has been done using a shutter made of Aklo No. 2 
heat-absorbing glass, which absorbs approximately 30 per cent of the 




FIG. 3. Paramount transparency stereopticon, looking 
down on optical system showing water-cell, heat-resisting 
experimental glass shutter, and field condensing system 
for plates. 

heat, and which is transparent enough not to have the disturbing 
flicker effect of a solid shutter (Fig. 3). 

It might be said that one psychological advantage in using a glass 
shutter in stereopticon shots is that the average director is not dis- 
turbed by shutter flicker on the screen which is always existent with 
the conventional type used in motion picture projection. 

The following figures will indicate the conditions found without a 
shutter, with an opaque shutter, or with a shutter of heat-absorbing 
glass: 



102 



F. EDOUART 



Vol 43, No. 2 



Photographic value of illumination 
Light incident upon eye 
Heat incident upon slide 



No Shutter 
Per Cent 

100 

100 
100 



Metal Shutter Glass Shutter 
Per Cent Per Cent 



100 

63 

63 



100 
91 
70 



It is evident from the above that the introduction of the metal 
shutter reduced the heat flux upon the plate by 37 per cent, and at 
the same time introduced the flicker characteristic typical of 35-mm 




FIG. 4. Paramount transparency stereopticon, operating side 
showing control panel on Mole-Richardson lamp, speaker system, 
and tachometer. 



background projection, whereas the heat-absorbing glass reduced the 
heat flux upon the plate by 30 per cent and caused a negligible 
flicker. With an increase of only 7 per cent in total heat on the plate, 
the shutter flicker was changed from a condition of 100 per cent 
illumination dropping to zero with the solid shutter, to a condition of 
100 per cent dropping to approximately 80 per cent, under which 
circumstances the presence of the glass shutter could hardly be 
noticed. Obviously this freedom from flicker is of considerable value 
in exposure determination. 



Aug., 1944 



STEREOPTICON PROJECTOR 



103 



The sole purpose of the shutter, whether glass or metal, is the pro- 
tection it affords the glass stereopticon plate from heat. The shutter 
motor is equipped with a magneto-type tachometer for determination 
of shutter speed when operating wild during tests and line-up opera- 
tions. When shooting, the shutter motor is interlocked with the 
camera motor by means of a standard interlocking distributor. 




FIG. 5. Paramount transparency stereopticon, 
showing right side and electrical hookup. 



The preference for a heat-absorbing glass shutter blade over metal 
may be realized if the increase of heat transmission amounting to 
approximately 7 per cent will not result in damage to the slide, emul- 
sion or breakage of the plate it is mounted upon. 

The light path between the water-cell and field condenser unit is 
completely enclosed with a tight-fitting hood so that no appreciable 
leak-light is present. It has a convenient piano hinge cover for easy 
access to the shutter assembly (Fig. 4). 



104 F. EDOUART Vol 43, No. 2 

The field lens unit consists of 2 condensers, mounted with the 
convex spherical curves face to face with the input and output piano 
surfaces to the outside. The colored slide is mounted on the output 
side, and the unit revolves around the optical axis through 180 de- 
grees so the slide may be leveled up for horizon line or angled either 
way at will. 

The slide is held away from the face of the field condenser by a 
specially designed 4-point holder, constructed to allow for the smallest 
point of surface plate contact, and to allow a cooling air stream to 
pass between the condenser and plate, preventing heat transmission 
and resulting in a minimum of plate breakage. 

A squirrel-cage type blower is mounted directly below the field con- 
denser and plate holder assembly, capable of delivering 200 cu ft of 
air per min, the speed of which is controlled by a switch and rheostat 
from the main control panel. A Venturi-tube principle of adjustment 
with directional air baffles located directly over the blower and under 
the slide, provides the best possible directional adjustment for both 
sides of the slide simultaneously. 

The objectives used are anastygmatic coated and consist of a 12-in. 
Astro /3.1 and 16-in. /4.5 Bausch andLomb, which are quickly inter- 
changeable in an adjustable focusing mount. When operating at 
approximately 225 amp using 16-mm positive carbons, the output of 
this equipment is in excess of 60,000 lumens. 

The main operating panel is located on the right and operating side 
at convenient height on which are mounted all necessary operating 
switches and a 2-way "talk-back" speaker connected with the camera 
operating table ahead of the projection screen. 

The whole unit is very portable; the base is all metal, built on the 
dolly principle and mounted on rubber tire castors. It weighs 1800 
Ib, and is equipped with convenient pan and tilt mechanisms and ad- 
justments which lock tightly. The base has 4 screw jacks which lock 
the unit solidly to the floor after being placed in correct stationary 
shooting position (Fig. 5). 

It is silent in operation for sound and is equally adaptable for both 
color or black-and-white stereopticon projection plates. 

This whole problem of natural color stereopticons with respect to 
transparency process work is new and has required the most in- 
genious and cooperative efforts of various departments. While we 
do not claim perfection, we know we have achieved a reasonably 
satisfactory result so far, which will improve with use. 



Aug., 1944 STEREOPTICON PROJECTOR 105 

The first step of accomplishment that of color print duplication 
was taken over by Earle Morgan and Roy Peck, heading up Para- 
mount's Still Processing Department and they have, after many 
difficulties, ably surmounted most of the problems of copying, con- 
trast control and color correction. The paper entitled "Duplication 
of Kodachrome Transparencies for Background Projection" was 
presented by Mr. Morgan. 1 

The second step and problem of transferring the duplicates has been 
very successfully accomplished by Barton H. Thompson of our 
Engineering Department, who has developed a rapid special control 
technique. The paper entitled "Kodachrome Transfer" was pre- 
sented by Mr. Thompson, research engineer. 2 

The number three step that of engineering and constructing the 
unit has been ably mastered by A. C. Zoulis, Chief Engineer of 
Paramount Engineering Department; Wilbur Silvertooth; Larry 
Brunswick; and the personnel of the Transparency Department. 

Were it not for the intelligent effort and perseverance of all these 
technicians, our stereopticons would have remained a difficult prob- 
lem. 

We have two of these units and have already utilized them in single- 
and dual-color projection. With the constantly increasing production 
of color motion pictures we feel we are on the right track to accomplish 
better results in color stereopticon transparencies. 

REFERENCES 

1 MORGAN, E. K.: "Duplication of Kodachrome Transparencies for Back- 
ground Projectors," /. Soc. Mot. Pict. Eng., 43, 2 (Aug., 1944), p. 93. 

2 THOMPSON, B. H.: "Kodachrome Transfer," /. Soc. Mot. Pict. Eng., 43. 2 
(Aug., 1944), p. 95. 



PRESENT AND PROPOSED USES OF PLASTICS IN THE 
MOTION PICTURE INDUSTRY* 

BARTON H. THOMPSON** 



Summary. A general survey of plastics as they apply to the motion picture 
industry, outlining molding and fabricating problems, basic material make-up, out- 
standing physical properties, and a general description of some of the actual usages 
of thermoplastic and thermosetting resins are given. The future of the many plastics 
is also briefly discussed. 



The adoption of plastics within the motion picture industry has 
been held up to a great degree by the war effort. Prior to the war 
many applications were made by using a plastic alone or in conjunc- 
tion with other materials. Although the plastic field is in its infancy ,. 
with the development of new resins and processes due solely to the 
war effort, in the future we may expect to accomplish with plastics 
what has heretofore been considered impossible. 

The word "plastic" is too new to have a clear definition. It is 
understood by many to be an animal or plant resin, or a synthetic 
organic material composed mainly of a resinous or cellulose deriva- 
tive binder. Actually, the majority of plastics are made from one or 
more of the following basic materials: Air, water, -coal, petroleum^ 
natural gas, limestone, salt, cellulose from wood or cotton, or sulfur. 

Plastics are classified as thermoplastic, thermosetting, and element 
reactive. The element reactive will not be discussed at length in this 
paper, but it is composed of resins which react to the elements, such 
as oxidation, and is used in coatings and surface finishes. 

Thermoplastics. These are synthetics except for a few natural 
resins, such as polyterpene and shellac, the cellulosics and the syn- 
thetic organic materials, which can be heated and molded into shape, 
and can be reheated and remolded from time to time. 



* Presented Oct. 18, 1943, at the Technical Conference in Hollywood. 
** Research Engineer, Paramount Pictures, Inc., Hollywood. 



106 



PLASTICS IN MOTION PICTURE INDUSTRY 107 

Thermosetting. These are plastics which set up or become rigid 
under heat and pressure or by heat alone. Unlike the thermoplastics, 
they may not be reheated to reform. In the motion picture industry 
we use all types of thermoplastics and thermosettings in some way, 
shape or form, and in many instances we are unaware that the ma- 
terial used contains a plastic. 

In this discussion of plastics I will present some of the present 
plastic applications, taking into consideration the type of plastics, 
why they are used, and how they are fabricated. In closing I will deal 
with the future of plastics as they pertain to the motion picture in- 
dustry. We will start with the thermoplastic field, and follow with 
the thermosetting. 



THERMOPLASTICS 

In the thermoplastic field we find the celluloses, vinyls, acrylics, 
shellac, polyterpene, styrenes, and synthetic fibers such as nylon and 
rayon. In our studio we do not have injection molding machines, 
extruders, or large capacity presses, all of which entail expensive 
hardened steel molds. Our one- or 2-piece production schedule 
would not permit such an expenditure; therefore we must rely on 
fabricating our needs from stock sheets, rods, and tubes furnished us 
by manufacturers or other sources of supply. 

Cellulose nitrate, the oldest of the cellulosics, is made from care- 
fully purified cotton having a high alpha cellulose content, and is 
treated with a mixture of nitric and sulfuric acids. This resin was 
developed to a commercial status in the middle of the 19th century by 
the incorporation of solid camphor. From that time on it has grown 
in proportion to the point where it is now used in many applications 
such as the replacement of tortoise shell, ivory, and other materials 
found in nature. 

The majority of work on motion picture film has been based on 
cellulose nitrate. As a matter of fact, approximately 95 per cent of all 
film used in Hollywood today is cellulose nitrate. Its outstanding 
properties are toughness, ease of fabrication, water resistance and 
moldability, but it has one great drawback, and that is its inflam- 
mability. This problem has been worked on by many concerns and 
it is found that with the use of certain plasticizers the inflammability 
has been reduced. Some handles of ladies' purses are made of ni- 



108 B. H. THOMPSON Vol 43, No. 2 

trate; the desired rod size is obtained, cut and bent to shape with the 
assistance of heat. The question immediately rises: why is nitrate 
chosen for the handle of a bag? The answer is because of its resist- 
ance to water, perspiration from the hand, toughness, and ease of 
fabrication. It is also used in the fabrication of eye shades, blotters, 
printed calendars, clock dials and crystals. 

Next in line is the cellulose acetate which is a resin made up simi- 
larly to nitrate, except that the treatment of cotton linters is with 
acetic acid and acetic anhydride in the presence of a catalyst such as 
sulfuric acid, instead of a mixture of nitric and sulfuric acid. It was 
commercially available about 1906 and was used in small quantities 
for the manufacture of noninflammable photographic film. During 
World War I it was used in the manufacture of airplanes as "dope" 
coatings. It is also used today in the motion picture industry in a 
similar way. 

The outstanding characteristic of this plastic, compared with cellu- 
lose nitrate, is that it is chemically stronger and has higher dielectric 
strength. Water resistance is not so good as that found in the nitrate, 
but this has been overcome by some manufacturers by the increase of 
acetyl content. Again, the imitation of natural products, such as 
mother-of-pearl, tortoise shell, and ivory, may be produced. The 
housing for an antenna used on a "prop" plane was made of an ace- 
tate. The material came to us in a flat sheet, was placed in an oven 
at the desired temperature, heated, removed, and stretched over a 
form. It was made in 2 pieces which were butted and, by capillary 
attraction of a suitable solvent, cemented together. The weld on this 
particular piece is probably stronger than the original sheet. Hat- 
boxes are also made of an acetate, drawn in a similar manner as the 
fabrication of the antenna housing. A plaque of a flying duck shows 
its possibilities for dyeing to any desired color. It also shows the 
possibilities of fabrication. The material is approximately 15 
thousandths of an inch in thickness, and has been drawn to better 
than three-fourths of an inch in less than a 2-in. space, indicating 
clearly that the material is ideal for motion picture uses. 

Cellulose acetate butyrate is made up in a manner similar to the 
acetate in that it uses a mixture of butyric and acetic acids and the 
anhydrides. This plastic was developed for the purpose of obtaining 
a more water-resisting resin, and its outstanding properties are, in 
addition to water resistance, weathering characteristics. This ma- 
terial is used on special films used in the motion picture industry, 



Aug., 1944 PLASTICS IN MOTION PICTURE INDUSTRY 109 

such as Kodachrome, where low moisture absorption, high dimen- 
sional and good weather resistance are demanded. It is also used in 
the manufacture of lacquers and is superior to the acetate not only 
in its weather resistance and resistance to water, but it has greater 
adhesion. 

We have a tubing made from ethyl cellulose, commonly known 
when highly plasticized as "ethyl rubber." It is made by the action 
of a strong alkali, such as sodium hydroxide on cotton linters, followed 
by a rather involved process. It can be plasticized to a rubbery con- 
sistency, or can be made to a rigid hardness. Its outstanding char- 
acteristic is its toughness at temperatures ranging from minus 78 F 
to plus 160 F. Its dimensional stability is excellent and it is the 
lightest of all the celluloses. Its density is 1.15. Transparency 
screens made from this material have proved ideal because the screens 
are strong, weathering characteristics are good, and age will not dis- 
color or make the film brittle. Another possible application within 
the motion picture industry is that of laminating cloth and fibers into 
desired forms or shapes. 

Another very useful plastic used within the industry is cellophane. 
This is a regenerated cellulose. Essentially 80 per cent is cellulose, 
the remainder plasticizers and waxes. Cellophane is manufactured in 
films, clear and colored, flame proof and moisture proof, in ribbons 
and strings, in tubes or soda fountain straws, in bags and in fabri- 
cated boxes for display purposes. In these many forms we adopt this 
material, cellophane, for use in draperies, wardrobes, and many 
forms of interior decoration and special effects. 

The vinyl resins are a group by themselves and are not used in this 
industry to any great extent. Basically, the resins are made from 
acetylene and acetic acid, or acetylene and hydrochloric acid, under 
exacting conditions. We find the vinyl acetate, vinyl chloride, vinyl 
chloride-acetate copolymer, the polyvinyl alcohol, polyvinyl butyral, 
vinyl acetal, and the vinyl formal. 

The most important of this group is the acetate. Its chief use, be- 
sides being the base for the manufacture of the alcohol, butyral, 
acetate and formal resins, is in the laminating field. These adhesives 
are excellent, and show great possibilities for post-war use. 

The vinyl chloride has proved very satisfactory for textile finishes, 
for waterproofing fabrics, whereas the molding compounds have been 
used to coat electrical cables where great wear, such as we have in the 
industry, is demanded. The copolymer of the vinyl chloride and 



110 B. H. THOMPSON Vol 43, No. 2 

vinyl acetate is used in sheet stock in laminated films, in coatings and 
in transcription records. 

The polyvinyl alcohol is a water-soluble resin and its typical 
applications are for adhesives, gelatin substitutes for photo-sensitive 
stencils, film where high tensile and tear strength is demanded, in. 
sizing of textiles, and as an admix for rubber latex. 

The vinyl acetal is used in the manufacturing of safety glass. 

All of these resins have excellent properties and great possibilities, 
but for the duration, unless used for actual war products, we must 
find substitute materials. 

We have a tubing made from vinylidene chloride resin, which is 
made from coke, lime, and brine. From coke and lime we secure 
acetylene. From brine we secure chlorine. The combination of 
acetylene and chlorine under exacting conditions produces a resin 
which is noted for its resistance to acids and alkalies, its noninflam- 
mability, and its high fatigue characteristics. Actual tests of this 
material have proved that it is one of the best in the field. It has 
been flexed more than three million times without showing a break- 
down. Pipes made of this material stand pressures up to 6000 Ib 
per sq in., with softening point of from 250 to 280 F. In this industry 
it is being used to replace copper tubing. 

The methacrylic resins are made by the polymerization of the mono- 
meric derivatives from the acrylic acids. These resins are noted for 
their superior transparency and for their abilities to "pipe" light. 
Within the industry they fit exceedingly well because of their flash 
and ease of fabrication. The procedure for making a picture frame 
is to take a rod of the acrylic or methacrylic resins, place it in an 
oven, heat it until it is flexible, twist it and form it into shape, hold in 
position, and then allow to cool. Furniture and ornamental personal 
properties, such as mirrors, cigarette containers, and jewelry boxes, 
have been used in our set dressings. 

Styrene is another interesting transparent material. It is made 
from ethyl benzine, and by the simple removal of the hydrogen we 
secure a monomer styrene, which is polymerized to give the poly- 
styrene. Styrene is noted for its chemical and water resistance, high 
impact strength at low temperatures, and its electrical qualities and 
low specific gravity. It is also noninflammable. Piping light is also 
possible. Coaxial cable used in the television field is made with the 
use of styrene beads. Other sound and electrical installations are 
also used within the industry. Because of the war effort, in our syn- 



Aug., 1944 PLASTICS IN MOTION PICTURE INDUSTRY 111 

thetic rubber progress we have constructed enormous plants for the 
manufacture of styrene. At the end of the war we may expect to see 
this transparent plastic become a large competitor in the plastic 
field, for today the cost is less than the methacrylics, acetates, and 
vinyls. 

Synthetic textile fibers, the rayons, proteins, nylons and vinyls, are 
used in draperies, wardrobes, coverings for furniture, and numerous 
other applications. 

The manufacturing process of nylon is complicated and exacting. 
The result is a synthetic linear polymide. Nylon is noted for its 
durability, strength, elasticity, colorability, and toughness. As nylon 
is being used approximately 100 per cent in the war effort, we will 
probably have to wait until after the war for a more general use of that 
property. 

The rayon fibers are broken down into 2 groups, the regenerated 
cellulose and cellulose derivatives. The viscose, nitro-cellulose, and 
cuprammonium are found in the former; in the cellulose derivatives 
are the acetate (esters) and ethyl (ethers) and a combination of the 
esters, ethers, or ester-ethers. They are noted for their high tensile 
strength and light weight. Threads finer than those of silk have been 
spun from these materials. The luster of these fabrics alone tells the 
story. 

The vinyls include several filaments, the two most important are 
Vinyon, a trade name of the Carbide and Carbon Chemical Company, 
which is a copolymer of vinyl chloride and vinyl acetate in the ap- 
proximate proportions of 90 to 10. The chemical and physical prop- 
erties are good, for they withstand acids and alkalies very well. They 
are tough and strong and are noted for their weathering character- 
istics. The second filament is the vinyladine chloride (Saran) mono- 
fils. From this resin have been manufactured seat coverings, substi- 
tutes for wire, fly screens, ropes, and many other applications where 
weathering characteristics are required, and which have more than 
proved their worth. 

Proteins, although not as important as other groups, have many 
applications. They are obtained from both animal and vegetable 
life. Milk and soybeans are the most commonly used. By special 
treatment a filament is obtained, but one great drawback to these 
fibers is that when they become wet they lose approximately 75 per 
cent of their strength. The greatest protein fiber application is that 
found in felt hats. 



112 B . H. THOMPSON Vol 43, No. 2 

THERMOSETTING 

The thermosetting field of resins is composed of the phenolics, 
ureas, melamines, furfurals, and a few others. In the motion picture 
industry, this material lacks the ease of fabrication of other resins 
in that large pressures and temperatures of 300 F and up are required 
for fabrication. There are a few exceptions to this, such as low- 
pressure laminates, no pressure laminates, and liquid cast phenolics. 
As the low-pressure laminates are just coming into the field we will 
wait until a future date for the discussion of this principle. Liquid 
cast phenolics will be discussed later in this paper. The 4 chief 
contenders in this field are the phenolics, furfurals, the ureas, and the 
melamines. 

In 1909 Dr. Baekeland developed a condensate material from the 
reaction of phenol and formaldehyde. This resin is used as a binder 
and is filled with such things as rags, string, cotton, walnut shell flour, 
cotton flock, and many others. These fillers determine the physical 
properties of the resin itself. For example, to secure a high impact 
strength material, a long fibrous filler is used, such as string. Many 
phenol formaldehyde resin parts, film spool rolls, and prefabricated 
parts are used on our various pieces of equipment. Laminated phen- 
olic sheets are also used in making specialty items, for example, the 
special gears for our cameras or single parts for equipment. Resins 
can be made from this material which give great shock resistance, 
heat resistance, extremely high impact strength, and high insulation 
value. However, all these properties depend upon the particular 
filler that is used. Phenols are available in dark colors only. 

Another of the phenol group is the phenol formaldehyde liquid 
casting resin. This resin lends itself readily to the industry in that 
inexpensive molds and low-cost equipment can be used in its fabrica- 
tion. By the introduction of an acid or alkali catalyst, this material 
will set to a rigid consistency. An example is a skull which can be 
cast in an inexpensive rubber mold, using a slush molding process; 
another is an artificial pineapple which can also be made in a like 
manner. 

Urea formaldehyde was commercially introduced into this country 
about 1928 and it is a truly synthetic resin since all the raw materials 
are derived from gases, ammonia, carbon dioxide, carbon monoxide, 
and hydrogen. The straight resin may be used as a bonding agent, 
such as is sometimes used in plywood panels, or it may be used to 
laminate sheets of paper or other sheet materials. It is also used 



Aug., 1944 PLASTICS IN MOTION PICTURE INDUSTRY 113 

\ 

in making up a resin with an alpha-cellulose pulp. This is probably 
its widest application, since the alpha-cellulose gives a white appear- 
ance. Dyes and color pigments may also be incorporated to give 
various shades as desired. 

An outstanding thermosetting resin which is just entering the field 
is the melamine resin. It has the qualities of being an ideal thermo- 
setting resin because it has the physical properties of the phenolic 
resins as well as colorability of the ureas. It is probable that this 
resin may be the answer to many problems heretofore unanswered in 
the thermosetting field. 

There are 2 other resins that have been adopted into the motion 
picture industry. One, borrowed from the paint industry; the other 
developed solely for a specific use. Both have the same final results 
the manufacture of "breakaway" glass and miscellaneous props. 
The one borrowed from the paint industry is a cyclo-paraffin resin, 
made by a very complicated process. The other is a resin developed 
by the Baker Oil Tool Company using as raw materials phenol, 
formaldehyde, and a catalyst, keeping at all times the phenol content 
in excess. Both these resins are water-clear in appearance; both 
have a critical melting point of around 300 F, and they shatter with- 
out leaving cutting edges. 

RUBBER 

Although this discussion is relative to plastics, I feel that the sub- 
ject of rubber should be mentioned. The war obviously has pro- 
hibited the use of rubber props and practically all other applications 
of rubber in the industry, but before the war rubber and rubber latex 
were sold in great quantities and made into props arrowheads, billy 
clubs, snakes, dishes, foliage for miniatures, artificial flowers, knives, 
and other applications such as vibration dampeners and other equip- 
ment installations. 

The latex rubber was the most widely used, again because of its 
ease of fabrication. Concentrated latex of 60 per cent was com- 
pounded, whipped up to a fluffy consistency by the common kitchen 
beater, poured into molds, placed in an oven, and cured. This proc- 
ess seems very simple but, as a matter of fact, it is a complicated and 
very difficult procedure. A tommy hawk used in pictures was made 
from milled stock in a metal mold and cured between hot platens of a 
temperature of 310 F and a closing pressure of the press. The prop 
billy was made in a similar manner except that the compounding was 



114 B. H. THOMPSON 

a sponge stock. The mold was partially filled, heat applied while 
the mold was closed, and the reaction of the compound formed a gas 
within the mass which filled the mold. We believe that rubber will 
return to the industry after the war with a greater importance than 
ever before. 

The future of plastics within the motion picture industry is un- 
limited in its possibilities when taking into consideration the new 
developments that are being made. The possible use might be the 
construction of complete sets where design demands. Props from 
these materials will be either soft and light or hard and heavy, de- 
pending upon the desire of the producer. Motion picture film, still 
retaining the desirable characteristics of cellulose nitrate, will be non- 
inflammable with no additional cost. Lenses, although this state- 
ment may be challenged by many, will be made of plastics, case- 
hardened to a possible hardness of quartz. Lens treatments will be 
made of a layer of plastics instead of the now technical vaporization 
of metals (to decrease light lost by reflection) . Plastic furniture will 
replace the present heavy woods and metals. Draperies, rugs, and 
seat coverings will be of. plastics. They will last not for just one 
picture, but may be saved and utilized in many. Equipment will 
be lighter, more durable, more easily fabricated, and much better to 
handle. Plaster sets which now weigh so much will be made lighter 
by the incorporation of a plastic which, in addition to its lightness, 
will increase its durability. Synthetic fiber materials will for once 
and all replace the natural fibers of today because of their greater 
life and colorability. Linings in our laboratories' developing tanks 
will be of plastic and last indefinitely. Plastics will outmode present 
processes now used in our make-up departments. Special effects re- 
quired by the industry, such as storms on the high seas, lava flows, 
and others now difficult to reproduce, will be simplified by the ap- 
plication of plastics. 

In conclusion, the plastic field is still in its infancy. No one can 
predict its ultimate accomplishments because of unlimited possi- 
bilities owing to chemical stability, heat resistance, low water ab- 
sorption, high tensile strength, noninflammability, colorability, 
lightness in weight, flexural stability, high dielectric qualities, and 
ease of fabrication. 



WAR STANDARDS FOR PHOTOGRAPHIC EQUIPMENT 
SPEED MILITARY INSTRUCTION* 

A. G. ZIMMERMAN** 



Ed. Note: Since the projects of the ASA War Committee on Photography and 
Cinematography-Z52 were initiated early in December, 1943, members of the Society 
of Motion Picture Engineers have collaborated with the Armed Forces, the War 
Production Board, and the motion picture industry, in organizing technical commit- 
tees to carry out these vital wartime needs. The Society was in an excellent position 
to make available the long experience and skill of its technical personnel, many of 
whom had already studied problems similar to those to be considered by the Armed 
Forces. 

Following the unanimous approval of the project by the Board of Governors, the 
membership of all SMPE technical committees offered their services wholeheartedly 
and were immediately organized into new groups to undertake the responsibility of 
preparing specifications for ASA War Standards. In addition to Mr. Zimmerman, 
Chairman of Subcommittee D, six other SMPE members serve as chairmen or vice- 
chairmen of Z52 subcommittees. 

Mr. Zimmerman's report of the completion of the principal project assigned to 
Subcommittee D is reprinted from Industrial Standardization. 

A schoolboy from the University of Minnesota, transplanted to a 
foxhole in the South Pacific, experiences a dislocation far beyond the 
imagination of most of us. That same boy must, further, be trained 
in the art of self-preservation against enemies, both natural and un- 
natural, and this training must be accomplished in an incredibly short 
period of time. Under ordinary circumstances an individual's 
knowledge of the customs, living conditions, and general nature of 
the people with whom he comes in contact is the result of years of 
association with his surroundings. War, however, gives no time for 
such experiences, for individual instruction, or even for ordinary 
methods of training to develop personal knowledge of the terrain, of 
enemy customs, customs of friendly natives, or an understanding of 

* Reprinted from Industrial Standardization, 15, 6 (June, 1944), pp. 109-12. 
**RCA Victor Division, Radio Corporation of America, Indianapolis, Ind.; 
Chairman, Subcommittee D, ASA War Committee on Photography and Cine- 
matography-Z52. 

115 



116 A. G. ZIMMERMAN Vol 43, No. 2 

new and unfamiliar equipment. The neophyte warrior must be 
educated in a matter of days, or even of hours, to kill, if he is not to 
be killed. 

The Chinese have a proverb to the effect that one picture is worth 
a thousand words. Faced with the problem of educating an Army 
and Navy in the least possible time, those responsible for military 
training have not ignored this ancient knowledge. As a result, the 
use of military arms, prevention of disease, and methods of assuring 
their general welfare under varying geographical conditions, have 
been taught to our fighting men in a remarkably short period of 
time. 

How has this been done ? It has been accomplished largely through 
the use of the motion picture. 

The Armed Forces believe that the motion picture, preceded or 
followed by printed commentary, is an able substitute for years of 
experience. Actual scenes, re-enacted by professional or amateur 
personnel, with an audible description of the action as it occurs, is an 
improvement of the Seven League Boot variety over the silent 
"movies." 

The fact that motion picture equipment was available immediately 
for the use of the Armed Forces can some day be written into the 
annals as a major contribution to the success of our campaigns. 

The contribution of the motion picture to the war effort does not 
stop with its service to the Army and Navy, however. Military 
success, as everyone knows, is dependent upon preparation, the 
amount and quality of equipment available, and the speed at which 
it is provided. When the war first started, the country as a whole 
was in need of schooled artisans to perform certain functions neces- 
sary for the design and manufacture of war materiel. In many cases 
the operators of machines had never heard of the product that they 
were to make, much less the machine they were to operate to make 
that product. Processes and machine tool operations were as 
foreign to them as though they had been created in a different world. 

Those in command of industrial organizations, therefore, as well as 
those in command of military organizations, were faced with the 
necessity of preparing, and releasing to the country in general, 
educational material which would make it possible for them to turn 
out production, to reduce scrap, and also to protect the health of 
workers so that schedules could b& met. For this, too, motion 
pictures furnished the means of education. 



Aug., 1944 WAR STANDARDS SPEED MILITARY INSTRUCTION 117 

We can be truly thankful that the equipment for carrying on such a 
program was available, and that the country was able to fall in line 
quickly on the preparation of training films. 

Fortunately, too, for our men who were called to the colors, the 
United States had been progressive in the development and partial 
standardization of the motion picture industry particularly in the 
35-mm or theatrical type of equipment. The nontheatrical or 16- 
mm type of equipment, however, utilized standard film but practically 
stopped there, in so far as standardization was concerned. It was 
unfortunate that the 16-mm equipment which was available at the 
time hostilities started was of such nature that no two projector 
mechanisms resembled each other. Each type of projector was 
manufactured from the designs of engineers varying in their opinions. 
Each was manufactured in an independent organization catering to a 
certain clientele. 

In peacetime, these manufacturers and consumers were satisfied 
(or at least partially so) by the performance of the equipment which 
they had produced or procured. Commercial 16-mm equipment had 
been designed for what had been considered at that time the most 
stringent application that of the classroom, or possibly the sales 
organization, which required the exhibition of not more than 2 or 3 
reels of film per day. The new or military requirement, on the other 
hand, was such that the machine had to be available for operation any 
hour of the day without failure. In addition, it had to be used under 
the most extreme conditions of vibration, shock, high humidity, 
extreme low- and high-ambient storage and operating temperatures, 
and salt-and-dust-laden atmospheres. Further, the using personnel 
could not always be carefully trained motion picture men any 
untrained GI might have to operate it under service conditions. 
And eventually the equipment would have to be repaired. Quick 
and easy replacement of parts would be necessary, and for example, 
in the South Pacific jungles, a service man could not be found around 
the corner and a source of spare parts found 2 miles down the street. 

Imagine, then, the dilemma of the Armed Services in attempting 
to obtain projection equipment which would be satisfactory for con- 
tinuous use in any climate, and under any conditions. 

Here is an example of conditions as they actually exist. Let us 
imagine that a convoy has left from a port of embarkation under 
sealed orders. During the interval of time between the embarka- 
tion and the arrival at the destination, the enemy has perfected a new 



118 A. G. ZIMMERMAN Vol 43, No. 2 

device with which the fighting personnel of the convoy have not been 
able to familiarize themselves. This information in the meantime 
has been transmitted to Facilities Branches in the States which have 
been able to prepare illustrative films, pointing out the advantages 
and weaknesses of the enemy's new technique. These films are flown 
to the convoy destination. 

Instructions are issued to brief the troops in as short a space of time 
as possible on the new technique to be used. The motion picture 
equipment is set up and operates almost continuously, with com- 
panies or even regiments in attendance, in order that the greatest 
number of men can be trained in the shortest space of time. 

Let us imagine that there are two machines available at this 
particular point, each of different manufacture. Let us carry our 
picture still further and imagine that a particular part of the machine 
wears out or proves defective under the constant "grind." Immed- 
iately the instruction efficiency is cut in half, since only half the 
personnel can be handled at a time. To carry our point still further, 
let us suppose that the Procurement Officers have done a perfect 
job in making spare parts available with the original equipment, but 
in this particular instance the spare parts that have arrived at the 
destination are for only one of the many types of equipment they are 
using. As a matter of fact, situations have occurred, and un- 
fortunately still do occur, where the spare parts available are not 
applicable to either type of equipment in use. 

Literally millions of lives depend upon the portrayal of this in- 
formation in the shortest possible time, and now, through no fault 
of the expeditionary forces, this information must be passed on either 
verbally or through a slow and tedious classroom operation. 

Conditions such as this became apparent immediately upon our 
advent into the war, yet the pressure was so great to get material, 
planes, rifles, ammunition, fuel, etc., that the training media motion 
picture equipment and films although considered highly important 
by the Armed Forces, was not considered sufficently important 
to create any form of standardization. The procurement offices 
obtained equipment from any source, going on the assumption that 
war is a wasteful procedure at best. This "civilian" equipment 
served as a "stop-gap" and despite its shortcomings has played a large 
part in our successes to date. 

As the war has progressed, however, the importance of improving 
the facilities for instruction work, as well as for field entertainment, 



Aug., 1944 WAR STANDARDS SPEED MILITARY INSTRUCTION 1 19 

has become more widely recognized. Farsighted individuals con- 
nected with training, engineering, and procurement in the Armed 
Forces have realized that the preliminary training given the troops 
is only one function which this equipment will be called upon to per- 
form. Our ultimate successes in the field must be followed by ad- 
ditional training, since the occupied countries, as they become such, 
must be educated to cooperate with the forces of democracy. 

This can best be accomplished through the medium of picture and 
sound. ^ 

For our immediate purposes, however, the Armed Forces are 
particularly interested in the development and design of equipment 
which will ask no quarter under any field service conditions. Such 
equipment, in other words, would be able to take its place alongside 
ordnance equipment in ruggedness and performance efficiencies. 

In addition, the Armed Forces are concerned with the solution of 
service problems, so that field failures, with their disappointments, 
can be reduced to a minimum, if not eliminated. In the short space 
of a few months these problems had become only too evident, and the 
Armed Forces had become only too conscious of the shortcomings of 
the commercial equipment available, to a great extent due to com- 
plete lack of standardization of the 16-mm equipment. Lens barrels, 
for example, were of different diameters, different tube complements 
were used (in some instances none of which were interchangeable 
between equipments), different projection lamps, different motors, 
etc., necessitated the stocking of literally thousands of parts. In some 
instances these parts will never be used because they may not be 
available for the equipment they fit at the time and place they are 
needed. 

With all this in mind, the Army Pictorial Service late in 1943 asked 
the War Production Board to arrange for standardization of 16-mm 
photographic equipment for use by the Armed Forces. 

First of the important standards completed by this War Com- 
mittee and approved by the American Standards Association as an 
American War Standard is the American War Standard Specifica- 
tion for a Service Model 16-Mm Sound Projector, Z52.1-1944. The 
standard was prepared by Subcommittee D of ASA War Committee 
Z52, under the chairmanship of the writer and the vice-chairmanship 
of J. A. Maurer. 

This specification, for portable 16-mm sound motion picture pro- 
jection equipment suitable for use under severe service conditions, 



120 A. G. ZIMMERMAN Vol 43, No. 2 

has been prepared through the coordinated effort of representatives of 
industry, the Armed Forces, and the War Production Board. Pro- 
jectors built to these requirements will give a performance that com- 
pares favorably in the quality of the image and sound with the 35-mm 
projectors used in movie houses all over the country. Packed in 
three 56-lb cases it will be able to go anywhere that a soldier can go. 
It is designed to withstand life in the rear end of a jeep; and to give 
long service in the moisture-laden atmosphere of the South Pacific. 
For ruggedness and dependability of performance, these specifications 
call for an operating performance which surpasses any 16-mm pro- 
jector at present on the market. 

One of the most important features of this proposed motion picture 
projector will be the ease with which it can be serviced. The develop- 
ment specifications call for easily interchangeable lenses, tubes, and 
other parts that will make these projectors easy to repair at isolated 
bases. 

The sound amplifiers, too, will have to be a lot sturdier than their 
commercial equivalents. The equipment throughout is designed to 
be as simple and as foolproof to operate as possible. Attention has 
also been given to its ability to withstand high temperatures, because 
it may be stored in shacks on deserts or transported in ships' holds 
stacked next to steam pipes. 

In order to insure a reasonably long life, one section of the new 
standard provides that the projector shall be operated continuously, 
except for time consumed in film replacement, for a period of 500 hr 
with the projection lamp turned on. At the conclusion of the 500-hr 
run, the projector is to be subjected to all other nondestructive tests 
and inspections called for in the specification. Other tests include 
a severe vibration test, tests for resistance to heat and humidity, 
and a concussion test that corresponds to the firing of a broadside on 
a cruiser, in order to be sure that the projectors will stand up under 
military transport and use. 

In its present stage, the new War Standard is intended as a de- 
velopment specification for use by the Armed Forces in procuring 
pilot models of projection equipment which will meet the basic re- 
quirements for use by the Armed Forces. Many of the test values in 
this standard are somewhat higher than those which have customarily 
been met in the past by projection equipment, which was designed 
originally for home or light industrial use. After pilot models of 
projectors meeting the requirements in this specification have been 



Aug., 1944 WAR STANDARDS SPEED MILITARY INSTRUCTION 121 

procured, certain of the requirements will be modified in order to 
obtain the best all-around compromise of performance with pro- 
duction. The revised specification, it is expected, will then be used 
by the Armed Forces for quantity procurement of 16-mm portable 
sound motion picture projection equipment. 

In preparing the standard, Subcommittee D carried out the 
following : 

(1} Correlated existing military specifications for materials, processes, and 
tests. 

(2) Approved or specified types of acceptable construction. 
(5) Stressed coordination of safety and facility of operation. 

(4) Established design and performance principles, limitations, requirements 
and tests mechanical, optical, and electrical. 

(5) Established maintenance requirement limits, particularly as regards field 
service problems. 

(6) Set up standard "tools" in the form of visual test films and equipment 
which could be used universally for design or acceptance testing. These include 
the following three American War Standards: Method of Determining Freedom 
from Travel Ghost in 16-Mm Sound Motion Picture Projectors, Z52.4-1944; 
Method of Determining Resolving Power of 16-Mm Motion Picture Projector 
Lenses, Z52. 5-1944; and Method of Determining Picture Unsteadiness of 16- 
Mm Sound Motion Picture Projectors, Z52.6-1944. 

Perhaps we have undertaken the first step in a Herculean task. 
The completion of this task may not be "just around the corner," 
but certainly we have hopes that this work will be a great advantage 
to the Armed Forces (in accord with their requirements) and in peace- 
time will be a yardstick by which the consumer and the manu- 
facturer are able to obtain a mutually satisfactory product. 

Following the approval of this standard as an American War 
Standard on April 28, the standard was submitted to the Armed 
Forces Committee on Photography and Cinematography. The 
Committee presented this American War Standard to the Joint 
Army-Navy Committee on Specifications and with minor editorial 
revisions, the specification was approved as Army-Navy Specifica- 
tion, JAN P-49, on May 31, 1944. 

The Chairman of Subcommittee D wishes to express and extend 
personal gratitude to those members of Subcommittee D, as well as 
the parent committee Z52 of the American Standards Association, 
who have contributed to the factual portions of the specification. 
Considering the problems, the speed with which the specification 
was completed was astounding. Particular credit should be given 



122 A. G. ZIMMERMAN 

to the personnel of the American Standards Association for their 
ability to have at their finger- tips information regarding previous 
standards and standards' activities which, in large measure, as- 
sisted Subcommittee D in moving along rapidly with the preparation 
of the specification. 

It has been said, "It is an ill wind that blows nobody good." 
In this case it took a war and our common defense to bring together 
the manufacturers of 16-mm motion picture equipment, in order 
that a satisfactory specification for military equipment could be 
prepared. It is expected that this will be merely a beginning in the 
program of standardization. 



AMERICAN MOTION PICTURE STANDARDS 

The five American Motion Picture Standards which appear on the 
following pages were recently adopted by the American Standards 
Association. Prior to that time these specifications had been ap- 
proved through the Committee on Standards as SMPE Recom- 
mended Practices and were published in that form in the JOURNAL 
of March, 1941, pages 262-66. 

The technical material in this present publication is identical with 
that previously given, the respective specifications having served for 
a reasonable period as Recommended Practices without evidence of 
need for any changes. This final step in the normal standardization 
procedure is thus evidence of the satisfactory completion of the work 
originated several years ago within our Society. 

F. T. BOWDITCH, Chairman 
Committee on Standards, SMPE 



123 



124 



AMERICAN MOTION PICTURE STANDARDS Vol 43, No. 2 



AMERICAN STANDARD 
For 35-Mm Motion Picture Film 


ASA 
Z22.34-1944 

Approved 
May 15, 1944 


CUTTING AND PERFORATING NEGATIVE RAW STOCK* 

(Revision of part of Z22.1 1930) 




r H i 





Millimeters 


Inches 


A 

B 
C** 
D 
E 
F 
G 
H 
L] 


35.00 + 0.00 
- 0.05 
4.75 =*= 0.013 
2.794 0.01 
1.85 0.01 
3.40 0.05 
28.17 0.05 
Not > 0.025 
2.08 0.025 
475.00 0.38 


1.378 + 0.000 
- 0.002 
0.1870 == 0.0005 
0.1100 0.0004 
0.0730 0.0004 
0.134 0.002 
1.109 0.002 
Not > 0.001 
0.082 0.001 
18.70 0.015 


** Diameter of circle of curvature. 
t L = length of any 100 consecutive perforation intervals. 



* For picture negative and certain special processes. 

These dimensions and tolerances apply to the material immediately 
after cutting and perforating. 



Aug., 1944 AMERICAN MOTION PICTURE STANDARDS 



125 



AMERICAN STANDARD 
For 35-Mm Motion Picture Film 


ASA 
Z22.36-1944 
Approved 
May 15, 1944 


CUTTING AND PERFORATING POSITIVE RAW STOCK* 

(Revision of part of Z22. 1-1930) 



o 




a 


3 

c 

c 


D 
D 


D 
D 

0_ 


c 
c 


D ! 
D 


c 


D.--- 



a 
a 
o 



CD 



t 
D 



C 





Millimeters 


Inches 


A 


35.00 + 0.00 


1.378 + 


0.000 




- 0.05 





0.002 


B 


4.750 =*= 0.013 


0.1870 


0.0005 


C 


2.794 0.01 


0.1100 


0.0004 


D 


1.98 0.01 


0.0780 


0.0004 


E 


3.40 0.05 


0.134 


0.002 


F 


28.17 0.05 


1.109 =*= 


0.002 


G 


Not > 0.025 


Not > 


0.001 


L** 


475.00 0.38 


18.70 * 


0.015 


R 


0.5 


0.020 




** L length of any 100 consecutive perforation intervals. 



* For positive prints and sound recording. 

These dimensions and tolerances apply to the material immediately 
after cutting and perforating. 



126 



AMERICAN MOTION PICTURE STANDARDS Vol 43, No. 2 



AMERICAN STANDARD 
For 35-Mm Motion Picture Film 


ASA 
Z22.37-1944 
Approved 
May 15, 1944 


RAW STOCK CORES 






Millimeters 


/</, 


A 

B 
C 


25.90 =*= 0.20 
50.00 0.25 
34.50 0.50 


1.020 
1.968 
1.358 


0.008 
0.010 
0.020 


Recommended Practice 


r 
s 


16.70 == 0.30 
4.00 == 0.20 


0.657 
0.157 


0.012 

== 0.008 



Bore A to fit freely to hub 25.40 0.1 mm or 1.000 0.004 inch diameter. 



Aug., 1944 AMERICAN MOTION PICTURE STANDARDS 



127 



AMERICAN STANDARD 
For 16-Mm Motion Picture Film 


ASA 
Z22.38-1944 
Approved 
May 15, 1944 


RAW STOCK CORES 






Millimeters 


Inches 


A 

B 
C 


25.90 0.20 
50.00 =t 0.25 
15.50 =fc 0.50 


1.020 =*= 0.008 
1.968 * 0.010 
0.610 0.020 


Recommended Practice 


r 
s 


16.70 0.30 
4.00 * 0.20 


0.657 =t= 0.012 
0.157 =*= 0.008 



Bore ^4 to fit freely to hub 25.40 0.1 mm or 1.000 =*=. 0.004 inch diameter. 



128 



AMERICAN MOTION PICTURE STANDARDS 



AMERICAN STANDARD 
For 35-Mm Motion Picture Film 


ASA 
Z22.39-1944 
Approved 
May 15, 1944 


SCREEN BRIGHTNESS 



The brightness at the center of a screen for viewing 35-mm motion 
pictures shall be 10 if ft-lamberts when the projector is running 
with no film in the gate. 



THE REQUIREMENTS OF MODERN PROJECTOR DESIGN* 
R. HOWARD CRICKS** 

We are all talking nowadays of post-war planning; one small aspect 
of it is the cinematograph projector which we may hope to see designed 
after the war. I propose considering this projector of tomorrow not 
so much as a piece of mechanism (this aspect of the subject has been 
very ably dealt with in a number of SMPE papers 1 ), but from the 
point of view of its purchaser, the exhibitor, and its user, the projec- 
tionist. 

Only professional static types of machines will be considered in 
this paper; but this does not necessarily rule out the 16-mm pro- 
jector, professional models of which will find many applications. 

For lack of a more comprehensive word, the term projector must 
include the picture mechanism, the illuminant, and the sound head, 
as a single entity. For a variety of reasons this approach is inevi- 
table. In spite of the conflicting commercial considerations involved, 
one or two manufacturers have approached this ideal, with beneficial 
results. 

Projector design had before the war reached a somewhat static 
state, when comparatively minor innovations, such as novel methods 
of lubrication, were cited as outstanding advances. The more dis- 
cerning of buyers assessed competing machines on the basis of less 
tangible but at least as important factors, such as the quality of 
materials and workmanship. 

The Demands of the Exhibitor. What then is the exhibitor en- 
titled to demand of a projector ? That it shall show a steady flicker- 
less picture, sharply focused at all times; the picture shall be lit 
with a light constant in color and intensity, over the whole area of the 
picture (except possibly the extreme corners) a light furthermore 
whose characteristics shall meet the exacting requirements of mod- 
ern color processes, and a light which shall remain consistent from 
hour to hour, and from year to year. 



* Reprinted from /. Brit. Kine. Soc., 6, 4 (Oct., 1943), pp. 116-31. 
** F.R.P.S.; read before the British Kinematograph Society, May 12, 1943. 



129 



130 R. H. CRICKS Vol 43, No. 2 

The sound must be free from all the defects to which the sound 
head may give rise : variations in film speed causing wow or flutter, 
faults in the scanning beam giving rise to treble losses or to waveform 
distortion. The sound head must be adaptable, so far as can be fore- 
seen, to possible developments in the art. 

The exhibitor will also demand that, so far as it is within the realm 
of mechanics, every change-over shall be perfect, with the minimum 
risk of a black screen, or of the "5-4-3" of the leader appearing on the 
screen, or of sentences being omitted from the sound track. 

The exhibitor will quite rightly demand that the projector shall be 
inexpensive to operate, both from the point of view of low mainte- 
nance costs, and of low current and carbon consumption. His nat- 
ural desire that it shall also be inexpensive to purchase may seem a 
little incompatible with the foregoing requirements. 

The Demands of the Projectionist. What does the projectionist 
demand of his equipment? First, it must be easy to thread, which 
means that the film path must be easily accessible, and a point 
noticeably overlooked in many modern machines have provision to 
facilitate threading in rack. For his peace of mind while running, the 
film path must be under observation. 

The machine must be kind alike to green prints, old copies, and bad 
splices. Means must be provided for cooling the gate. The machine 
must be easy to clean and maintain, and in particular there must be no 
risk of oil leaking on to the film. 

Not the least important demand of the projectionist is a simple and 
effective change-over system a system which needs no skill beyond 
the ability to press a button when the "motor" cue appears on the 
screen, and again when the "over" dot is seen. The simplicity of 
change-over is much facilitated by the conception of the whole pro- 
jector as a single unit. This matter of change-over is stressed, because 
to the inexperienced projectionist, every change-over is apt to be a 
test of nerve. 

Many well-meaning inventors have sought to provide the projec- 
tionist with an entirely automatic change-over system, functioning 
without the intervention of the projectionist. No doubt such a sys- 
tem will one day emerge, but a necessary preliminary is a different type 
of cue to be embodied on every film for instance, a length of fre- 
quency track on the perforation edge. 

Safeguarding the Films. Two other parties have also a certain 
interest in the design of our projector. The first is the renter, whose 



Aug., 1944 MODERN PROJECTOR DESIGN 131 

interest lies in the fact that it is his property that will be ruined by a 
defective machine. The second is the public, who, in return for their 
admission fee are entitled to be safeguarded from injury, whether by 
fire or panic, or less spectacularly by eyestrain or headaches due to a 
badly focused, badly lit, or unsteady picture. 

There is yet another consideration. Without regard to the present 
immunity of our projection rooms from dangers of fire, our legislators 
will probably endeavor at some future date to make the use of non- 
flammable film compulsory this notwithstanding the failure of such 
legislation in other countries. The mechanical properties of safety 
base are of course much inferior to those of nitrate; while improve- 
ments will no doubt be made, past experience suggests that closer 
attention should be paid to the minimizing of film wear and tear. 

Optical Requirements. First let us consider the optical aspects. 
Our ideal should be that in every cinema, no matter what its size, 
a screen of a size appropriate to the auditorium should be lit with a 
standard intensity, and with a variation of intensity across the screen 
falling within specified tolerances. In this country, 2 in America, 3 and 
in Germany, 4 a considerable amount of work has been done in these 
directions, but it is to be feared that the industry is slow to take ad- 
vantage of it. 

A suitable screen intensity agreed in this country and the U.S.A. 
is between 7 and 14 ft-L, with a variation not exceeding these limits 
in any part of the screen, or from any seat in the auditorium. (Rather 
lower standards have been accepted in Germany.) Actually, some 
cinemas have an intensity as low as 2 or 3 ft-L, while in the opposite 
direction are the news-theaters and various private theaters, where 
readings of 35 and 40 ft-L are not uncommon. (These high illumina- 
tion levels may provide some explanation for the exhibitor's repeated 
complaints of excessively dense prints.) 

Every manufacturer of projection equipment should ensure that 
every installation complies with the standard requirements, by pre- 
paring detailed recommendations of type of equipment, lens aper- 
ture, arc current, and carbon size, capable of giving a lumens output 
suitable for any particular condition. 

One point often overlooked is that the optical system of the arc 
lamp, the projector gate assembly and heat shields, and the lens, 
should have the same effective aperture. One sometimes sees a mod- 
ern large-aperture lens used unnecessarily, being only partially filled 
by the cone of light from the arc. and in other cases a considerable 



132 



R. H. CRICKS 



Vol 43, No. 2 



amount of light wasted inside the lens by its having a smaller aper- 
ture than the arc condenser system (this also causing deterioration 
of the lens due to excessive heating) . 

Another factor is occasionally that the construction of the projector 
gate and heat-shields gives rise to vignetting, so not permitting the 
maximum aperture of the arc and lens being efficiently utilized (Fig. 

i). 

Arc Lamp. The arc should need the minimum of attention, and 




FIG. 1. Faults in projector optical systems; (^4) lens incompletely flashed, 
(5) light wasted around lens, (C) vignetting by heat shield. 



should provide the minimum of scope for individual preferences 
once the adjustments have been set for the particular running 
conditions. The motor feed should be capable of running a double 
reel without hand adjustment and incidentally, the projectionist 
must be educated to allow it to do so, and must realize that any at- 
tempt to interfere with a properly adjusted feed means a loss of con- 
sistency in the light on the screen. 

To maintain consistency of light, some form of arc control is essen- 
tial, either by rotation of the positive carbon, or by magnetic means. 
There is still room for experiment on the latter; a properly designed 



Aug., 1944 MODERN PROJECTOR DESIGN 133 

magnetic field cannot only stabilize the arc, but materially increase 
the light output. 5 The difficulty at present is the wide variation in 
its effects with slight changes in arc current or voltage. 

An obvious difficulty in maintaining consistency is the gradual 
depreciation of the optical components. The silvering of the arc 
mirror gradually burns off, and condensers become spattered with 
copper. Such depreciation could be somewhat reduced by an efficient 
cooling system, but these factors constitute probably the greatest 
obstacle in the maintenance of screen brightness. 

Maintaining Consistency of Light. The gradual, and to the 
projectionist imperceptible, variation in screen illumination due to 
these factors suggests that some device should be provided whereby 
a constant check could be kept upon the light output of the pro- 
jector. 

At the Odeon, Leicester Square, a device is installed which meas- 
ures the light reflected from the screen, and so permits of a constant 
check upon the actual screen brightness. 6 This device however in- 
troduces two variables which it might seem preferable to measure 
separately : the varying reflectivity and directivity of the screen, and 
the atmospheric conditions of the auditorium. If in addition some 
measuring device were embodied in the projector, it would enable 
variations in the actual projection equipment to be located. 

It is not sufficient merely to measure the light output from the arc, 
for this would fail to take into account the possibility of alteration in 
the adjustments of the arc in relation to the projector a very com- 
mon source of inefficiency and light loss. The ideal arrangement 
would seem to be a light-sensitive cell which could be slipped into a 
preset position between the gate and the objective, so that readings 
could be taken daily before the start of the performance. 

If it were desired not only to measure the total light passing through 
the gate aperture, but also to check the evenness of illumination over 
the aperture, such a cell might be used in conjunction with a movable 
mask, placed in the gate, to enable readings to be taken in say five 
separate areas within the aperture. Any such device would necessi- 
tate a regular plotting of the readings by the projectionist, in order 
that a continual check might be kept upon the performance of the 
equipment. 

Film Buckle. Having procured our desired intensity and even- 
ness of screen illumination, the next essential is a sharp focus of the 
picture. The modern objective lens is probably the most perfect 



134 R. H. CRICKS Vol 43, No. 2 

component of the projector. Existing types of gates, however, fall 
short of perfection in regard to maintenance of the film in the focal 
plane. 

The increasing aperture of modern projection lenses apertures of 
//1. 9 are quite customary draws attention to an important factor in 
the design of the projector gate : the avoidance of film buckle. 7 With 
new prints it is rarely a problem ; but if a small exhibitor has had the 
wisdom to install first-class optical equipment, and yet has to take 
his copies after a number of runs in front of the powerful illuminants 
of larger halls, his projectionist is apt to find considerable difficulty 
in maintaining the center of the picture in focus. The problem is 
therefore two-fold : first, the reduction of gate heat to minimize film 
buckle, and secondly, the improvement in gate design to hold buckled 
film flat behind the lens. 

The principle of curving the film longitudinally in order to prevent 
lateral buckle is familiar in the sound head and in other types of 
equipment; it is also used in some 16-mm projectors. Obviously the 
actual frame of film being projected must be held flat, and it would 
seem desirable also that there should be a straight path from the 
aperture to the intermittent sprocket; but a curved upper part of the 
gate would surely prove of assistance. 

Gate Cooling. There is probably no better method of gate cool- 
ing than that employed in a Continental machine: the construc- 
tion of the gate as a hollow casting, through which passes a stream 
of water. Air cooling has also been used. Either has the minor 
objection of needing external connections to the projector. 

Use may also be made of two other expedients : the interposition in 
the light beam of a number of heat-shields, gradually masking the 
light beam so that the minimum of stray light falls upon the actual 
gate; and the principle of the reflection of unwanted light and heat 
by means of a polished face behind the gate. 

A number of years ago, I put forward some proposals on these lines, 
which however met with little response. The idea is shown in Fig. 2. 

The casting 24a forms the first heat-shield; 25 is a circular heat- 
shield, intercepting the light beam twice. A current of air is pro- 
vided by forming the drum shutter 22 in the form of a turbine fan, 
with blades 23, so cooling both the heat-shield and the gate. To over- 
come the objection of such systems, that the shutter fan is apt to 
draw in dirt from the atmosphere upon the film, I proposed drawing 
the air past a viscous filter, built into the projector, 8 



Aug., 1944 



MODERN PROJECTOR DESIGN 



135 



Projection Rake. A cinema without a projection rake is today 
an exception. Yet the only expedient for obtaining a reasonably 
sharp picture over the screen is to cant the screen slightly a device 
which actually increases the distortion observable from the front 
seats. The use of a keystone-shaped gate mask may help to conceal 
the distortion without improving the focus. The extent of this dis- 
tortion is perhaps little realized. 9 



.M 




FIG. 2. Proposals for gate cooling system. 

The still photographer overcomes an analogous difficulty by the use 
of a tilting back; unfortunately, if the projector gate were made to 
tilt, an improvement in definition would be accompanied by an in- 
crease in distortion, or vice versa. On at least one projector, it is 
possible for the lens to be adjusted vertically, but this seems an un- 
suitable method, since it is obviously desirable to work on the optical 
axis of the lens. Whether it would be possible to design an optical 
system to work in this manner is a question for opticians to decide. 



136 



R. H. CRICKS 



Vol 43, No. 2 



Emulsion Pick-up. A cooler gate would of course help in re- 
ducing trouble from pickup of emulsion from green prints. If how- 
ever we are to continue to have to run unprocessed green prints, 
further steps are necessary. 

The invariable cause of emulsion pickup is some cavity or scratch 
in the runners; the emulsion lodges in these cavities, bakes hard, and 
acts as a small chisel, gouging out a groove from the edges of the film, 
and straining the perforations in doing so. The intelligent pro- 
jectionist will of course clean his gate regularly (but never with steel, 




FIG. 3. Maltese crosses giving 90- and 70-degree shift periods. 

which may cause scratches) ; but with all the care possible, scratches 
do occur in the runners. The use of hardened and ground steel for 
the runners would, I suggest, assist materially in preventing this 
source of annoyance and possible danger. 

It would, too, be a sound idea if the gate runner or aperture plate 
were made easily interchangeable, and the projectionist were en- 
couraged to change it between reels, so permitting of a more thorough 
cleaning than is possible in position. If the aperture plate were made 
fairly robust, its replacement between reels would assist in keeping 
the film path cool. 

Intermittent Motion. This brings us to the heart of the projector. 



Aug., 1944 



MODERN PROJECTOR DESIGN 



137 






the intermittent motion. Many people fail to grasp the funda- 
mental reason for the employment of a Maltese cross in the projec- 
tor, and one hears frequent suggestions that various types of claw 
motions would be quite suitable if they could be made sufficiently 
robust. Such suggestions fail to take account of the fact that no 
practicable type of claw motion will produce a picture shift of less 
than 90 degrees with reasonably good acceleration, and if the shift 
period is not less than 90 degrees, the shutter will have an efficiency 




Mi/lisecoads 



FIG. 4. Velocity and acceleration curves of standard Maltese cross move- 
ment (calculated). 



of less than 50 per cent (it is essential for the avoidance of flicker that 
both blades of the shutter should be of approximately equal angle). 

Actually, the shift period of a Maltese cross, geometric considera- 
tions notwithstanding, is appreciably less than 90 degrees, due to the 
slight slackness of the striker pin within the cross slots; most pro- 
jector shutters actually have blades of less than 90 degrees. 10 A still 
quicker shift period would of course permit of narrower shutter blades 
and greater light transmission; but it is only with a theoretical shift 
period of 90 degrees that tangential entry and leave of the striker 
pin in the slots becomes possible. The old Pathe" machine had a shift 



138 R. H. CRICKS Vol 43, No. 2 

period of about 70 degrees; from the commercial point of view the 
merit of this design was the increased sales of Maltese crosses, due to 
frequent breakages (Fig. 3). 

But it is quite possible to design movements with a quicker shift 
period. An example was the Powers movement, in which the Maltese 
cross was replaced by a four-pin cross, actuated by a rather compli- 
cated cam. This had a shift period of about 60 degrees. 

The objection to any speeding up of the shift period is that of 
film wear a point of particular importance if nonflammable base 
should ever become compulsory. The importance of this point will 
be appreciated from Fig. 4, which shows the calculated velocity and 
acceleration curves of 35-mm film fed by a standard Maltese-cross 
movement at 24 frames per sec; it will be seen that the acceleration 
reaches at its maximum the enormous figure of over a mile per second 
per second! 

These curves are however purely theoretical. From attempts I 
have made to record the movement curve of film in an actual pro- 
jector running at normal speed, it appears that other complications 
have to be taken into account play of the striker pin in the slots, 
and resultant bouncing of the cross, and notably the resilience of the 
film, due to which the full theoretical acceleration is never reached. 

Reduction of Film Stresses. It says much for the mechanical 
properties of film base that it should withstand this enormous ac- 
celeration. The force needed to produce the acceleration will be 
given by the equation : 

fi = m.a 

The mass m will of course depend upon the length of film subjected 
to the intermittent movement; if we reckon the weight of the film 
as one-thousandth of a pound, then the force / will, according to the 
theoretical curves shown, reach a maximum of nearly 6 Ib applied, 
remember, 24 times per sec. 

But this is far from being the full extent of the film stresses. A 
certain force / 2 is required to bring the film to rest. One cannot as- 
sume that this is effected entirely by gate tension; undoubtedly a 
large proportion of the deceleration is effected by the sprocket. 
But there must still remain a considerable proportion of the decelera- 
tion curve due to the gate, and this force must with existing types of 
gates be overcome also during the acceleration period. In practice, 
an additional force / 3 is encountered, representing the difference be- 



Aug., 1944 MODERN PROJECTOR DESIGN 139 

tween static and dynamic friction, plus the projectionist's margin of 
safety to ensure a steady picture. Thus the total force exerted upon 
the film during the period of maximum acceleration is: 



If the gate could be so designed as to exert tension only for the de- 
celeration period, and not during acceleration, the terms / 2 and / 8 
could be almost eliminated, and F would be reduced to possibly a half. 
The lifting gate is well known in camera mechanisms, but its compli- 
cations make it unadaptable to the projector. Nevertheless, a similar 
principle could, I suggest, be applied electrically for instance, by 
means of an intermittently energized magnetic system. Given some 
such system, the stresses on the film could be reduced to perhaps one- 
third, and a speeded-up shift period could usefully be embodied, per- 
mitting of narrower shutter blades. 

Since the force needed to accelerate the film is directly proportional 
to the mass of the film to be accelerated, which is itself dependent 
upon the length of the gate and of the loops, theory would suggest 
that the general preference for a long gate is incorrect : that the gate 
should be kept as short as possible, consistent with the provision of 
an adequate and not harsh deceleration of the film, and of lateral 
guidance of the film. 

Shutter Efficiency. We come next to the shutter. In addition to 
its task of masking the movement of the film, a shutter has two 
requirements : it must eliminate visible flicker, and it must neverthe- 
less pass the maximum amount of light to the screen. A rear shutter 
also has the advantage of reducing gate heat. 

But any attempt to increase the efficiency of the shutter except by 
a reduction of shift period seems rather pointless. The innumerable 
"patent" shutters of a few years ago admittedly passed considerably 
more light, but only at the expense of the blacks of the picture, since 
their principle was the use of perforated or translucent blades, or of 
translucent sectors of complementary colors. In either case, the 
extra light passed was distributed over the whole of the picture, so 
reducing contrast; and surely contrast in the picture is even more 
important than brilliancy. 

Other than by these incorrect methods, the maximum gain in il- 
lumination that can be obtained by modifying the shutter design is 
of the order of 10 per cent or 15 per cent; a corresponding gain in il- 



140 R. H. CRICKS Voi 43, No. 2 

lumination can be obtained by a slight improvement in the loading 
or handling of the arc, or by quite a trifling increase in lens aperture. 

The drum shutter shows a certain advantage, since the cutoff is ef- 
fected simultaneously in two planes, and from top and bottom of the 
picture. In existing conditions, however, a drum shutter has a serious 
disadvantage : it can be efficiently designed only for one given optical 
system. Any difference in the angle of light cone from the arc mirror, 
for instance, will reduce its efficiency. This provides a further argu- 
ment in favor of the construction of the arc and the projector head as 
an entity. The combination of front and rear disk shutters, as in one 
American machine, or of shutters rotating in opposite directions, 
gains the same advantage of top and bottom cutoff, without the dis- 
advantage mentioned. 

Racking Systems. The problem of racking, although it has 
been closely studied from the mechanical aspect, does not seem to 
have received its due attention in regard to the needs of the projec- 
tionist. On many projectors, it is possible to see whether the film 
is threaded in rack only by performing gymnastic contortions, plac- 
ing one's eye in front of the lens while holding a torch behind the 
gate. It is only of recent years that a proposal I first made many 
years ago has been adopted : that a duplicate aperture should be pro- 
vided at the top of the gate, through which the picture could be viewed 
by means of a racking lamp. 

An even better proposal is that, right up to the moment of change- 
over, an auxiliary optical system should project a small image of the 
frame in the gate upon the wall of the projection room. This would 
not only ensure correct racking, but would effectively prevent the 
last few feet of the standard leader being projected on the screen a 
fault by which even West-end audiences are nowadays edified. 

Further, if the switching of this auxiliary illuminant were inter- 
locked with the intermittent movement and with the racking lever, 
two frequent causes of misracks would be eliminated: threading 
while the intermittent sprocket is in course of movement, and not 
returning the racking lever to its midway position. 

Unlimited Racking. It is perhaps pandering to the less efficient 
of projectionists to suggest that the modern racking system, with its 
limited travel, falls short of perfection. It is true that if the film is 
properly spliced and properly threaded, the racking handle need never 
be touched ; but it may be likened to the bit of rubber at the end of a 
pencil it does make allowance for human errors. One occasionally 



Aug., 1944 MODERN PROJECTOR DESIGN 141 

sees a projectionist when racking his picture move the racking system 
to its extremity in one direction, and then have to move it in the op- 
posite direction to eliminate a misrack. 

Many years ago, the late W. Vinten constructed an experimental 
projector with unlimited racking in other words, the racking handle 
could be turned indefinitely in either direction. True, the design 
involved a fearsome collection of differential gears to provide for 
shutter phasing and to keep the film loops constant; but some sim- 
plified system should be capable of construction. 

Sound Head Construction. I have so far considered the argu- 
ments in favor of regarding the projector mechanism and the arc as 
a single unit. The arguments in favor of constructing the mute and 
sound heads as a single unit are still stronger. 

First conies the simplification of mechanical design. To transmit 
the drive from the sound head to the separately built mute head ne- 
cessitates quite a collection of gears both the so-called adapter gears 
which carry the drive as far as the shaft at the bottom of the mute 
head, and the gears inside the mute head carrying the drive from this 
rather awkwardly placed driving shaft to the various components. 
If on the other hand the sound head is built integrally with the mute 
head, a single vertical shaft carries the drive to all components. 

The unit construction of mute and sound heads has other advan- 
tages : the less complicated mechanism is capable of gaining speed more 
rapidly; the smaller number of gears lessens the risk of gear- tooth 
ripple being imparted to the film, and, together with the modern 
trend towards nonmetallic gears, makes for quieter running. 

Filter Systems. One point upon which designers are today 
unanimous is in condemning the original type of sound head, with 
its stationary sound gate and the sound sprocket immediately below 
it. Instead, the sound is scanned upon a rotary drum, and be- 
tween this and the driving sprocket are provided film loops either 
entirely free, or carried on sprung rollers which effectively smooth 
out any sprocket ripple. With unstable material such as film, it is 
impossible for the sprocket teeth to mesh correctly without impart- 
ing ripple to the film, and this ripple appears in the speakers as 
flutter after poor acoustics the most common cause of unintelligible 
speech. 

The modern types of sound head mechanical filters notably the 
magnetic drive or rotary stabilizer 11 give a virtually complete free- 
dom from wow and flutter. Many equipments are however consid- 



142 



R. H. CRICKS 



Vol 43, No. 2 



erably less perfect, and much of the unintelligible speech heard today 
must still be attributed to flutter due to inefficient filter systems. 

An important point is the isolation of the sound head or at least 
the whole of the scanning system from projector vibration. It is 
not uncommon for the exciter lamp filament to be vibrated at picture 
frequency (since the chief source of vibration is the Maltese cross) 
and so modulate the light reaching the photocell, resulting in the re- 
production of cross noise in the speakers. The isolation of the sound 
head by rubber cushioning is an important advance. 12 

In this connection, it is obviously desirable that the exciter should 




u 



FIG. 5. Two types of sound-head optical systems. 

have a thick filament, better able to resist vibration. From this 
point of view, the 6-v, 1-amp lamp included in the B.S. exciter lamp 
specification 13 is definitely unsuitable, and in my view its use should 
be discouraged. 

Optical System. Optically, the principal essential of the sound 
head is that it shall provide a scanning slit sufficiently narrow to en- 
sure the reproduction of the highest frequencies found on the track. 

Two distinct types of optical systems are employed (Fig. 5). In 
the earlier type, the image of the slit is projected upon the film; 
whatever may be the theoretical width of the slit image on the film, 
the converging light rays from the objective diverge within the thick- 
ness of the emulsion, and light scatter and halation occur, resulting 



Aug., 1944 MODERN PROJECTOR DESIGN 143 

in the effective width of the image being considerably greater than its 
theoretical width, and so affecting high-frequency reproduction. 

In the alternative type, a magnified image of the sound track is 
projected upon the slit. In view of the considerable enlargement of 
the image in one case seven diameters a higher scanning standard 
is assured. Image diffusion is probably less than in the case of a pro- 
jected slit, while, since the physical dimensions of the optical compo- 
nents are greater, any given departure of the film from the optical 
plane as by polygoning on the scanning drum will have less effect 
upon the focus of the image. 

On the other hand, the former type has the advantage that all the 
components are built into the one tube, sealed from dirt and more im- 
mune from the mishandling. 

Stereophony. We have for years been awaiting the introduction 
of the push-pull track in the cinema. But judging by recent de- 
velopments, it seems probable that instead we shall have to pre- 
pare for stereophonic reproduction. 

Any idea that the double-film systems of the Fantasound type will 
be widely adopted can in my view be dismissed. But there seems 
every indication that simpler systems, embodying a twin sound track 
and a control track on the single picture film, will be the next popular 
innovation. 14 It is to be hoped that before post-war manufacture 
commences, an authoritative decision may be taken on the type of 
system to be adopted, and on standards to be employed. 

Open or Enclosed Mechanism? A practical point upon which 
there is much diversity of opinion is whether the film path through 
mute and sound heads should be open or enclosed. A projectionist 
does like to be able to see every inch of the film path; on the other 
hand, an enclosed projector will naturally keep cleaner, and, according 
to American regulations, is safer from the point of view of fire risk. 

I suggest that there is only one way in which these conflicting re- 
quirements can be met : by the use of a Perspex molding for the whole 
of the cover. The film path would thus be completely visible from 
take-off to take-up, yet effectively shielded from dirt. 

Another component that might usefully be made of Perspex (if regu- 
lations permit) is the spool-box door. There is no machine in which 
the aperture allowed for viewing the spool really permits one to judge 
how much film is left, and most projectionists find it necessary, in de- 
fiance of regulations, to open the spool-box door. 

Take-up Design. A. point in projector design which still falls 



144 



R. H. CRICKS 



Vol 43, No. 2 



short of perfection is the take-up. Innumerable suggestions have 
been made which would cause the tension to increase as the reel in- 
creases in size, so reducing the pull on the first few feet of film. 15 It is 
rather remarkable that none of these suggestions has found general 
favor. 

Even with the present rather crude friction device, two minor points 
which would lead to some improvement are the use of ball bearings 
for the take-up shaft, so enabling a lighter tension to be used ; and the 
provision of a spring buffer to eliminate the sudden snatch on the film 
in starting up. 

Change-Over Devices. It seems inconceivable that, although the 
need for repeated change-overs has been recognized for the past 30 
or 40 years, it is only of recent years that change-over devices have 



N2 N?l ' N2 N2 SOI/NO H? I 

RUNNING RUNNING MOTOR ON a PifTURt MOTOR Off 




\ I / 





FIG. 6. Proposed change-over system. 



become an integral part of certain projectors; today, their adoption 
is far from universal, and devices for fitting to projectors have met 
with a wide sale, while one still sees the change-over carried out by a 
length of string or chain from one lamp-house dowser to the other. 

On older equipment, a change-over is really a two-handed job, 
while even today on most installations, the projectionist is required to 
make separate and simultaneous change-overs of picture and sound, 
often at widely separated knobs. A point which is often overlooked 
is that the projectionist should, at the change-over, be always stand- 
ing at the side of the incoming machine in case of any trouble at the 
beginning of a reel. 

The whole of the picture and sound change-over should, I main- 
tain, be made from either of two interconnected switches, one to the 



Aug., 1944 MODERN PROJECTOR DESIGN 145 

right of each projector (Fig. 6). When No. 1 projector is running, 
the switches will be in position 1 ; when the motor cue-dots appear, 
the projectionist, standing by No. 2 projector, moves the switches to 
position 2, and the motor of No. 2 machine starts; in moving from 
position 2 to position 3 on the appearance of the "over" dots, the pic- 
ture and sound are both changed over. Then the motor of No. 1 pro- 
jector can be switched off from either switch, by moving the knob to 
position 4. In changing over in the opposite direction the sequence is 
reversed. There seems no difficulty in applying such a principle, al- 
ways provided that picture and sound mechanisms are considered as a 
single unit. 

Standardization. There has been much talk recently of the need 
for standardization of projection equipment. But I feel that the 
exhibitors who have been foremost in urging this have a slightly 
different idea from that implicit in existing standards. 

Hitherto, the insistence has been on the fundamental point, that 
any film must be capable of running on any projector. The ideas of 
the exhibitor, I feel, run rather on the lines of ensuring that spare parts 
shall be interchangeable on all types of projectors. 

Within limits, this is a perfectly legitimate basis of standardization, 
and one which might well be considered by the Society and by the 
British Standards Institution, to the extent perhaps of specifying as 
"Recommended Practice" that, for instance, intermittent sprockets 
should have a bore of either 5 /ie in. or 7 /32 in., with specified tolerances, 
and with an agreed method of fixing. 

Manufacturers would however quite justly object to any standardi- 
zation of a nature likely to inhibit progress, and for this reason it may 
be felt undesirable to stabilize such dimensions to the degree suggested 
by a formal standard. 

Future Developments. I have so far confined myself to minor 
improvements in equipment substantially of existing types. There 
are however two major developments of the future which will, I am 
convinced, have a far-reaching effect on the design of projection equip- 
ment. The first is the substitution of the discharge lamp for the 
arc, and the second is the development of the nonintermittent prin- 
ciple. 

As an instance of the revolutionary design rendered possible by the 
substitution of the arc by a discharge lamp, we have the Philips pro- 
jector, seen just before the war. 16 Here, we have both projector 
heads in the one unit, one above the other, with the capillary-type wa- 



146 R. H. CRICKS Vol 43, No. 2 

ter-cooled mercury lamp, immediately behind the gates. This ma- 
chine has of course been designed with the possibility in mind that it 
can be run by a single projectionist a common thing in projection 
rooms everywhere except in this country, but not a practice to be 
commended. 

No engineer would dispute the value of the nonintermittent principle. 
There are of course technical difficulties to be overcome; but I feel 
that the chief difficulty is the conservatism of our industry, in con- 
junction with the fact that, until the recent requirements of stock 
economy, nobody was particularly interested in enabling prints to 
have a longer working life than at present, since their life is already 
adequate to satisfy the number of bookings generally obtainable. 
It is the small exhibitor who would chiefly gain, in improved condition 
of copies, by the installation of nonintermittent projectors in the 
larger cinemas. However, the prospect of having to use nonflammable 
stocks may alter this situation. 

The only striking nonintermittent projector we have seen has been 
the Mechau Arcadia, made by Leitz, and demonstrated just before 
the introduction of sound. 17 Notwithstanding its obvious advan- 
tages for sound reproduction, the fact that it could not be easily 
adapted to standard types of sound equipment damned it as far as 
this country was concerned, although it is I believe still used on a 
small scale in Germany. 

I see no reason why the nonintermittent machine should be so much 
more cumbersome and expensive than an intermittent machine 
rather the reverse. The difficulties of the nonintermittent principle 
are well known, 18 and one may hope that post-war research may make 
it a practical proposition. 

If the nonintermittent projector were to come into general use 
there would be some advantage in reducing the separation between 
picture and sound on the film, so taking advantage of the steady con- 
tinuous motion needed for projection, to scan the track. 

We may look still further into the future to the day of the all- 
electronic cinema to which the President referred in the recent sym- 
posium. 19 When large-screen television is perfected and universally 
installed, it might be preferred to run the film program on the televi- 
sion equipment rather than install separate film projectors. We could 
then have a nonintermittent scanning apparatus with purely elec- 
tronic compensating arrangements from many aspects an ideal ar- 
rangement. 



Aug., 1944 MODERN PROJECTOR DESIGN 147 

REFERENCES 

1 /. Soc. Mot. Pict. Eng., July, 1937, pp. 23, 94; May, 1938, p. 597; Mar., 
1939, p. 325; Mar., 1942, p. 262. 

J /. Brit. Kine. Soc., May, 1938, p. 68; July, 1939, p. 153. B. S. Spec. 930, 
1940. 

8 /. Soc. Mot. Pict. Eng., July, 1937, p. 40. Better Theatres, Aug., 1941, p. 24; 
Sept., 1941, p. 33. 

4 Kinotechnik, Aug., 1939, p. 196. 

cf. Br. Pat. 381,952. 

/. Brit. Kine. Soc., July 1939; p. 153. 

7 /. Soc. Mot. Pict. Eng., July, 1943, p. 69. 

8 Br. Pat. 431,416. 

9 Ideal Kinema, Nov., 1936, p. 40. 

10 JT. Soc. Mot. Pict. Eng., Mar., 1942, p. 277. 
" /. Soc. Mot. Pict. Eng., Apr., 1937, p. 337. 
12 Ideal Kinema, June, 1936, p. 50. 

18 B. S. Spec. 1015, 1942. 

14 Better Theatres, Dec., 1940, p. 30. /. Soc. Mot. Pict. Eng., Oct., 1941, p. 147. 
Internal. Proj., Dec., 1941, p. 10. 

16 Ideal Kinema, Apr., 1937, p. 42. Kine. Weekly, Jan. 18, 1940, p. 41. /. 
Soc. Mot. Pict. Eng., Mar., 1942, p. 256. U. S. Pat. 1,398,680. 

16 /. Brit. Kine. Soc., July, 1939, p. 170. 

17 Filmtechnik, Oct. 9, 1937, p. 163. 

18 7. Soc. Mot. Pict. Eng., Jan. 1933, p. 3. 

19 /. Brit. Kine. Soc., Jan., 1943, p. 3. 

DISCUSSION 

MR. A. G. D. WEST: Manufacturers should take to heart many of the points 
made by the lecturer. The nonintermittent system and the discharge lamp in 
particular should receive close attention. 

MR. S. T. PERRY: Are not the Mechau and Philips projectors silent? 

THE AUTHOR: The Mechau was in its original form; but I understand that 
sound models are in use in Germany. The Philips machine was originally de- 
signed for sound; it is exceedingly compact, with the amplifiers contained in the 
pedestal. 

MR. S. T. PERRY: Personally, I feel it would take a lot to cancel out the ease of 
operation of present projectors. An objection of the twin machine would be the 
difficulty of replacing the mechanisms in the event of an emergency. 

MR. C. G. HEYS-HALLETT: The accessibility of the Philips projector is in- 
finitely superior to outfits where the amplifiers are mounted on the wall. The 
mechanisms are quite easily replaced. 

MR. H. R. A. DE JONGE: Mr. Perry's views must be considered. Manufac- 
turers have to think seriously before manufacturing these modern designs ; when 
they are offered for sale, everyone wants the older types. 

THE AUTHOR: It is up to the Society to educate the industry regarding de- 
velopments in design. 



148 MODERN PROJECTOR DESIGN 

MR. P. G. A. H. VOIGT: If we in this country do not press on with development, 
somebody else will. 

A MEMBER: What is the power of the Philips lamp? 

THE AUTHOR : One kilowatt, plus 500 w loss in conversion gear. D-c must be 
used, because of mains flicker, although an alternative would be to increase pro- 
jection speed to 25 frames per sec. Discharge lamps have been made up to 2Ve 
kw. One French firm marketed a 16-mm machine with a discharge lamp, but the 
weight and bulk of the rectifier was a disadvantage. 

MR. S. T. PERRY: The color of the light from the discharge lamp is unsuitable 
for color films. 

THE AUTHOR: Yes, in demonstrations I have so far seen, there is considerable 
distortion of color; the reds turn maroon. For black-and-white, the color is 
very pleasing. The difficulty of the discontinuous spectrum may some day be 
overcome by means of luminescence. 

MR. R. T. DEALEY: Is there any reason why discharge lamps should not be 
adapted to existing types of projectors, in place of the arc lamp? 

THE AUTHOR: I see no objection at all. The special optical system would of 
course be required. 

MR. M. SMITH: Would the discharge lamp make much difference to the gate 
temperature? 

THE AUTHOR: Quite an appreciable difference, although I have no figures. 

MR. A. DAVIS: For back-projection in the studio, where the arcs are usually 
over-run, we have used carbon dioxide for cooling the gate. Is there any reason 
why this should not be generally used? 

THE AUTHOR: I went into the question of using solid CO 2 for gate cooling some 
years ago. The only objection seems to be the cost; it worked out at several 
pence an hour, and I felt that few exhibitors would consider even such a small 
expenditure justified. 

MR. F. N. G. LEEVERS : We have come to accept the Maltese cross as the stand- 
ard motion for projectors. I have for some time used a six-sided Maltese cross 
for 16-mm machines; it is the smoothest motion I have come across. 

MR. W. HARCOURT: We have also used a Maltese cross for 16-mm both in 
printers and projectors; it is more satisfactory and steadier than the claw, and 
causes less wear to the film. 

THE AUTHOR: The objection to the Maltese cross for 16-mm machines is that a 
four-sided cross necessitates an intermittent sprocket too small to give sufficient 
wrap for the film. A six-sided cross means that the striker pin does not enter 
tangentially, and the motion is noisy and subject to wear. 

MR. P. G. A. H. VOIGT: You mentioned some experiments which suggested that 
the actual acceleration and deceleration of the film was not in accordance with 
your calculated curves. Might this not be due to damped waves set up in the 
film? 

THE AUTHOR: My own suggestion is that the discrepancy is due to the film 
bouncing on the sprocket teeth, but the two effects might well be connected. 

MR. C. G. HEYS-HALLETT : To my mind, the most important part of Mr. 
Cricks' paper was his references to screen brightness. It is most important that 
standards should be set up whereby exhibitors would be able to buy the right 
equipment for a particular type of hall. 



CURRENT LITERATURE OF INTEREST TO THE MOTION PICTURE 

ENGINEER 



The editors present for convenient reference a list of articles dealing with subjects 
cognate to motion picture engineering published in a number of selected journals. 
Photostatic or microfilm copies of articles in magazines that are available may be 
obtained from The Library of Congress, Washington, D. C., or from the New York 
Public Library, New York, N. Y., at prevailing rates. 



American Cinematographer 

25 (May, 1944), No. 5 
Thomascolor (p. 154) 
Walt Disney Studio A War Plant (p. 156) 

British Kinematograph Society, Journal 

7 (Jan.-Mar., 1944), No. 1 
Coated Lenses (p. 7) 

Recent Advances in the Physics of Colour (p. 10) 
Picture Definition (p. 14) 

Fundamentals of Photo-Electric Emission (p. 19) 
Sound Measurement and Analysis (p. 21) 

Educational Screen 

23 (Apr., 1944), No. 4 
Post-War Implications for Education in the Audio-Visual 

Programs of Our Armed Services (p. 153) 
The School Made Film for Purposes of Supervision of 

Instruction (p. 157) 
Motion Pictures Not for Theatres, Pt. 58 (p. 161) 

International Photographer 

16 (Apr., 1944), No. 3 
Shooting Snow in Sunlight (p. 5) 
"Mille," the Dolly (p. 8) 
No Camera Is Better than Its Finder (p. 10) 

16 (May, 1944), No. 4 

New Portable Processing, Printing and Editing Kit (p. 5) 
Time and Temperature Control (p. 22) 
Future of Technicolor (p. 29) 

International Projectionist 

19 (Apr., 1944), No. 4 

Action of Complex Electric Currents in Projection Room 
Circuits (p. 7) 



A. WYCOFF 
C. NATER 



K. M. GREENLAND 
H. V. WALTERS 
L. H. BEDFORD 
A. SOMMER 

J. O. ACKROYD 



P. WENDT 

M. SHERMAN 
A. E. KROWS 



E. O'TOOLE 

J. YOLO 
H. BOYCE 

D. WOOD 
M. LESHING 
H. T. KALMUS 



H. B. SELWOOD 



149 



150 CURRENT LITERATURE 

Motion Picture Projection in Italy (p. 10) A. NADELL 

Television Today, Pt. VII Television Transmitters 

(p. 20) J. FRANK, JR. 

Motion Picture Herald 

155 (Apr. 29, 1944), No. 5 
Is Projection Above and Behind Screen Practical? (p. 85) C. E. SCHULTZ 



We regret to announce the death of J. S. MacLeod ', Active member of 
the Society, on July 3, 1944. 



FIFTY-SIXTH 
SEMI-ANNUAL TECHNICAL CONFERENCE 

OF THE 

SOCIETY OF MOTION PICTURE ENGINEERS 

HOTEL PENNSYLVANIA, NEW YORK, N. Y. 

OCTOBER 16-18, 1944 



Officers in Charge 

HERBERT GRIFFIN, President 

EMERY HUSE, Past-President 

LOREN L. RYDER, Executive V ice-President 

E. ALLAN WILLIFORD, Secretary 

W. C. KUNZMANN, Convention Vice-President 

D. E. HYNDMAN, Engineering Vice-President 

A. C. DOWNES, Editorial Vice-President 



Directory of Committee Chairmen 

Atlantic Coast Section C. R. KEITH, Chairman 

Papers Committee BARTON KREUZER, Chairman 

C. R. DAILY, Vice- Chair man, West Coast 

Publicity Committee. .. JULIUS HABER, Chairman, assisted by 

MESSRS. DESFOR and BIDWELL 

Registration and Information W. C. KUNZMANN 

Reception and Local Arrangements. .E. I. SPONABLE 
Fifty-Sixth Semi-Annual Dinner- 
Dance D. E. HYNDMAN 

Membership and Subscription 

Committee JAMES FRANK, JR., Chairman 

Hotel and Transportation O. F. NEU 

Ladies Reception Hostess MRS. E. I. SPONABLE 

Projection 35-mm H. F. HEIDEGGER, Chairman, assisted by 

Members New York Projectionists Local 
No. 306 
16-mm M. W. PALMER 

151 



152 SEMI-ANNUAL TECHNICAL CONFERENCE Vol 43, No. 2 

HOTEL RATES 

The Hotel Pennsylvania management extends to SMPE members and guests 
the following per diem rates, European plan : 

Room with bath, one person $3 . 85-$7. 70 

Room with bath, two persons, double bed 5. 50- 8. 80 

Room with bath, two persons, twin beds 6 . 60- 9 . 90 

Parlor suites: living room, bedroom, and bath. .$10.00, $11.00, $13.00 and $18.00 

RESERVATIONS 

The Hotel Pennsylvania room reservation cards will be mailed to the member- 
ship of the Society early in September. If attending the Fall Conference, return 
your card with checked accommodations immediately to the hotel so your reserva- 
tion, which is subject to cancellation prior to October 15, can be booked and 
confirmed. No accommodations will be guaranteed unless confirmed by the hotel 
management. 

REGISTRATION 

The Fall Conference registration headquarters will be located on the 18th floor 
of the hotel adjacent to the Salle Moderne where all technical and business 
sessions will be held. Members and guests are expected to register, the fee for 
which is used to defray Conference expenses. 

TECHNICAL SESSIONS 

Members and others who are contemplating presenting papers during the Fall 
Conference can greatly assist the Papers Committee in the early assembly of 
their program by mailing in the titles of their papers not later than September 1, 
and complete manuscripts not later than October 1, to the East or West Coast 
Papers Committee chairmen, or to the Society's New York office. Your co- 
operation is solicited so that pre-Conference notice of the papers which will be 
presented can be given. 

FIFTY SIXTH SEMI-ANNUAL DINNER-DANCE 

The Fifty-Sixth Semi- Annual Informal Dinner- Dance, award presentations, 
and social get-together, will be held in the Hotel Georgian Room, on Tuesday 
evening, October 17, (dress optional). In order to make the necessary hotel ar- 
rangements for this function, the Committee must know in advance the number of 
persons attending the dinner. Therefore, tickets may be procured or reservations 
made at the Society's office at the Hotel Pennsylvania, or through D. E. Hynd- 
man, Chairman of the Dinner- Dance Committee, on and after October 1. Checks 
should accompany requests for tickets and should be made payable to W. C. 
Kunzmann, Convention Vice-President. 

LADIES' RECEPTION HEADQUARTERS 

Although there will be no prearranged ladies' entertainment program during 
the Fall Conference, a reception parlor will be available in the hotel for the 
ladies' daily get-together and open house with Mrs. E. I. Sponable serving as 



Aug., 1944 SEMI-ANNUAL TECHNICAL CONFERENCE 



153 



reception hostess. The ladies are invited to attend the Conference social func- 
tions. Ladies attending the Conference should register to receive badges and 
identification cards. 

MOTION PICTURES 

Conference identification cards issued to registered members and guests will 
be honored through the courtesy of the following de luxe motion picture theaters 
in New York : 

CAPITOL THEATRE 

PARAMOUNT THEATRE 

RADIO CITY Music HALL 

ROXY THEATRE 

WARNER'S HOLLYWOOD AND STRAND THEATRES 

There are many entertainment attractions available in New York to out-of- 
town members and guests, and information concerning these may be obtained at 
the hotel information desk or at the SMPE registration headquarters. 



Monday, October 16, 1944 

9: 00a.m. Hotel, 18th Floor: Registration. 
10: 00 a.m. Salle Moderne: Morning Session. 
12: 30 p.m. Luncheon period. 

2 : 00 p.m. Salle Moderne: Afternoon Session. 

8 : 00 p.m. The program for the evening of this date will be announced later. 

Tuesday, October 17, 1944 

9: 00 a.m. Hotel, 18th Floor: Registration. 
10: 00 a.m. Salle Moderne: Morning Session. 
12: 30 p.m. Luncheon period. 

2: 00 p.m. Salle Moderne: Afternoon Session. 

8 : 00 p.m. Georgian Room: Dinner-Dance and social get-together. The evening's 
program will be announced later. 

Wednesday, October 18, 1944 

9: 30a.m. Hotel, 18th Floor: Registration. 
10: 00 a.m. Salle Moderne: Morning Session. 
12: 30 p.m. Luncheon period. 

2 : 00 p.m. Salle Moderne: Afternoon Session and Adjournment. 

IMPORTANT 

When you receive your hotel room reservation card, please return it 
immediately if attending the Fall Conference. There will be no rooms 
available or guaranteed unless booked in advance of the Conference dates. 

W. C. KUNZMANN 

Convention Vice- President 



MEMBERS OF THE SOCIETY 

LOST IN THE SERVICE OF 

THEIR COUNTRY 



FRANKLIN C. GILBERT 



ISRAEL H. TILLES 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

Vol43 SEPTEMBER, 1944 No. 3 

CONTENTS 

PAGE 

High-Quality Communication and Power Transformers 

E. B. HARRISON 155 

The Duplex Loudspeaker J. B. LANSING 168 

Sixteen-Mm Color to 35-Mm Black-and-White 

C. H. DUNNING 174 

What to Expect of Direct 16-Mm L. THOMPSON 178 

A Rerecording Console, Associated Circuits, and Con- 
stant B Equalizers 

W. C. MILLER AND H. R. KIMBALL 187 

Reproduction of Color Film Sound Records 

R. G6RISCH AND P. G6RLICH 206 

Book Review 214 

Current Literature 214 

Fifty-Sixth Semi- Annual Technical Conference 216 

Society Announcements 219 

Committees of the Society 221 

(The Society is not responsible for statements of authors.) 

Contents of previous issues of the JOURNAL are indexed in the 
Industrial Arts Index available in public libraries. 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

HARRY SMITH, JR., EDITOR 

ARTHUR C. DOWNES, Chairman 

Board of Editors 

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KBLLOGG 
CLYDE R. KEITH ALAN M. GUNDELFINGER CHARLES W. HANDLBY 

ARTHUR C. HARDY 
Officers of the Society 
^President: HERBERT GRIFFIN, 

133 E. Santa Anita Ave., Burbank, Calif. 
* Past-President: EMERY HUSE, 

6706 Santa Monica Blvd., Hollywood, Calif. 
*Executive Vice-President: LOREN L. RYDER, 

5451 Marathon St., Hollywood, Calif. 
** Engineer ing Vice-President: DONALD E. HYNDMAN, 

350 Madison Ave., New York, N. Y. 
^Editorial Vice-President: ARTHUR C. DOWNES, 

Box 6087, Cleveland, Ohio. 
** Financial Vice-President: ARTHUR S. DICKINSON, 

28 W. 44th St., New York, N. Y. 
* Convention Vice-President: WILLIAM C. KUNZMANN, 

Box 6087, Cleveland, Ohio. 
^Secretary: E. ALLAN WILLIFORD, 

30 E. 42d St., New York, N. Y. 
^Treasurer: M. R. BOYER 

350 Fifth Ave., New York, N. Y. 

Governors 

**FRANK E. CARLSON, Nela Park, Cleveland, Ohio. 
"fCHARLES W. HANDLEY, 1960 W. 84th St., Los Angeles, Calif. 
**EDWARD M. HONAN, 6601 Romaine St., Hollywood, Calif. 
*JCLYDB R. KEITH, 195 Broadway, New York, N. Y. 
**JOHN A. MAURER, 117 E. 24th St., New York, N. Y. 
*HOLLIS W. MOYSE, 6656 Santa Monica Blvd., Hollywood, Calif. 
*WILLIAM A. MUELLER, 4000 W. Olive Ave., Burbank, Calif. 
*H. W. REMERSHIED, 716 N. La Brea St., Hollywood, Calif. 
**EARL I. SPONABLE, 460 W. 54th St., New York, N. Y. 
*JOSEPH H. SPRAY, 1277 E. 14th St., Brooklyn, N. Y. 
*REEVE O. STROCK, 111 Eighth Ave., New York, N. Y. 
**WALLACE V. WOLFE, 1016 N. Sycamore St., Hollywood, Calif. 

*Term expires December 31, 1944. 
**Term expires December 31, 1945. 

fChairman, Pacific Coast Section. % 

{Chairman, Atlantic Coast Section. 



Subscription to non-members, $8.00 per annum; to members, $5.00 per annum, included 
in their annual membership dues; single copies, $1.00. A discount on subscription or single 
copies of 15_per cent is allowed to accredited agencies. Order from the Society of Motion Picture 
Engineers, fnc., Hotel Pennsylvania, New York 1, N. Y. 

Published monthly at Easton, Pa., by the Society of Motion Picture Engineer*, Inc. 

Publication Office, 20th & Northampton Sts., Easton, Pa. 

General and Editorial Office, Hotel Pennsylvania, New York 1, N. Y. 

Entered as second-class matter January 15, 1930, at the Post Office at Easton. 

Pa., under the Act of March 3, 1879. Copyrighted, 1944, by the Society of Motion 

Picture Engineers. Inc. 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

Vol 43 SEPTEMBER, 1944 No. 3 



HIGH-QUALITY COMMUNICATION AND 
POWER TRANSFORMERS* 



E. B. HARRISON** 

PART ONE 
POWER TRANSFORMERS AND FILTER REACTORS 

The sound engineer is waging a never-ending fight against ex- 
traneous noises entering a sound channel. One of the greatest 
sources of noise is the complex field created by the many power 
transformers and filter reactors in the system. Of the methods 
of elimination, that which is aimed at the reduction of the fields at 
their source is perhaps the most effective. There are several ways 
of reducing, and in some instances virtually eliminating, the stray 
fields radiating from these coils. 

For a transformer of conventional shell-type design with a given 
load rating, the shape and magnitude of the stray field depends on 
several factors, among which are the size of the transformer, flux 
density at which the transformer core is operated, the geometry of 
the core structure, and the magnetic shielding surrounding the 
structure. Since the stray field increases with the size of the trans- 
former and increases with increased flux density, it follows that 
there is an optimum size, other things being equal, which will result 
in the lowest stray field. 

In any shell-type design utilizing a single coil, this lowest stray 
field will still be large enough to modulate the program in adjacent 
audio transformers and tubes. Its influence can extend to audio 
transformers as much as 3 to 4 ft away, which means practically that 
even though the power equipment is located away from the audio 
components of its own channel, it may affect other channels in 
adjacent racks. 

* Presented Oct. 20, 1943, at the Technical Conference in Hollywood. 
** Altec Lansing Corporation, Hollywood. 

155 



156 



E. B. HARRISON 



Vol 43, No. 3 



It has been found desirable, therefore, to produce a series of trans- 
formers designed for operation in crowded racks. These transformers 
are built on a core-type magnetic circuit having 2 coils astatically 
balanced. They occupy less space than the conventional design, 
and operate at high efficiencies, that is, with low temperature rise. 

Fig. 1 is a sketch of the core structure around which this type of 




FIG. 1. 



transformer is built. It can be shown that for the most efficient de- 
signs the following approximations hold: 

(1) The core loss in watts is equal to the copper loss in watts. 

(2} The mean length of the magnetic circuit is equal to the mean length of the 

copper circuit. 
(3} The cross-sectional area of the core is equal to the cross-sectional area of 

the window. 

The geometry of the structure is such that the coils are long 
solenoids with their magnetic axes closely spaced, resulting in an 
almost perfect astatic balance of their fields. Measurements made 
on transformers built around these proportions indicate that the 



Sept., 1944 COMMUNICATION AND POWER TRANSFORMERS 157 

field is so low that moderately shielded low-level input transformers 
may be operated next to them without hum pickup. 

The narrow width of the core was chosen to insure a fairly uniform 
flux distribution which is further aided by the method of stacking, 
reducing the usual areas of high flux density with their resulting high 
loss. 

In a fully interleaved core assembly (i. e., 1 and 1) the reluctance 
of the air gap at the lamination joint causes a portion of the flux to 

LAMINATION JOINTS 
AIR GAP ^ 



INTERLEAVED iai 



AIR" GAP 



^ r=. -=.--=- --- - ~- ^ - -Jl '-J3-- 

... ' ' 

INTERLEAVED 282 

FIG. 2. 

seek a path through the adjacent laminations, raising the flux den- 
sity and losses therein (Fig. 2). Now, when the extent of the inter- 
leaving is reduced by stacking the laminations in pairs (2 X 2), the 
reluctance of the leakage path through the adjacent laminations is 
increased, because the length is effectively increased, forcing a 
greater portion of the flux to flow across the joint air gap. The re- 
duction of high flux density areas by this method of stacking in- 
creases the permeability of the total core structure as shown in Fig. 3, 
where the solid line represents the permeability of the 1X1 stack, 
and the dotted line that of the 2 X 2 stack. 

Fig. 4 shows a transformer built around the foregoing principles. 



158 



E. B. HARRISON 



Vol 43, No. 3 



Note that at all points the transformer is close to the case housing it, 
providing more rapid dissipation of heat to the outside air. Note 
also that almost two-thirds of the coil surface is exposed, that no 
thick-walled coil sections exist, and that core heat is conducted to and 
radiated fjjpm the 2 ends of the core which also are close to the 
housing. 




FIG. 3. 

Fig. 5 illustrates the compactness of the design in comparison 
with a conventional unit of the same rating. Both transformers 
were designed to operate with the same temperature rise less than 
40 C. Consider particularly the comparison of the operating efficien- 
cies, weights, and chassis space occupied. 

TM-579 TW-604 

Volt-amperes 350 360 

Efficiency , 96 per cent 92 . 7 per cent 

Watts dissipated 15 27.7 

Weight, Ib 17Va 29V< 

Chassis space, sq in. 23 47 



Sept., 1944 COMMUNICATION AND POWER TRANSFORMERS 



159 



vSince their fields generally are of the most vicious type, being 
made up of not one but many frequencies, the companion power 
filter reactors' were built around the same principles of design. The 




FIG. 4. 




FIG. 5. 



astatic balance is carried to the point of locating the air gap in the 
center of the coils where the possibility of leakage is lowest (Fig. 6). 
In practice, 2 stacks of U-shaped punchings are clamped together 
in the coils against insulating spacers to maintain the correct gap. 
The clamps and bolts are so located that very little magnetic flux 



160 



E. B. HARRISON 



Vol 43, No. 3 



passes through them (Fig. 7). The removal from the magnetic cir- 
cuit of these relatively high coersive force steels eliminates all of the 
harmonics generated by the common commercial type of filter choke 
which is clamped together between steel frames secured by bolts 
passing through the core, all of which carry magnetic flux. The Q 
of the choke is raised appreciably, so that for a given inductance 
substantially better filtering action is obtained. Incidentally, audio 
chokes designed on these principles have shown a Q of 70 at 1000 
cycles. 




FIG. 6. 



PART TWO 
AUDIO TRANSFORMERS 

The last few years have witnessed great improvements in audio 
transformer design. Not the least of these are due to the many kinds 
of core material now available. Audio transformers operate at low 
inductions, ranging from several thousand gausses in a high-level 
output transformer down to one gauss and less in low-level input and 
interstage transformers. The low induction hysteresis and eddy 
current losses must be small, and the initial permeability should be 
high. Since eddy current losses vary inversely with the resistivity 
of the core material, and as the square of the thickness of the lamina- 
tions, the core stock must also have high electrical resistivity, and be 
used in thin sheets. 



Sept., 1944 COMMUNICATION AND POWER TRANSFORMERS 



161 



The presence of eddy currents in the core results in a phenomenon 
known as skin effect or shielding effect. This effect is merely the 





FIG. 7. 





FIG. 8. 



observed result of the loading caused by the secondary current cir- 
culating around the individual laminations. The counter-emf 
generated by these currents prevents the penetration of flux to the 
center of the plate or lamination. This means that as the frequency 



162 E B.HARRISON Vol 43, No. 3 

is increased, the effective core area decreases, the total flux is less, 
the permeability is less, and the inductance of the winding goes 
down. 

To take full advantage of the high initial permeability the core 
should be laid out with as short a path as possible, having a minimum 
of high reluctance joints, best located actually within the windings 
surrounding parts of the core. It is fortunate that the requirements 
for small-size high inductance transformers lie in the low-level field 

?. f444lH7 8 wfH | EM|^^ 

TP-2oMtfUflSf ORMF.ft '< 







tsveu * tsee 



FIG. 9. 



where the transformer has nothing to do but present to the tube 
grid a considerably enlarged facsimile of the input signal voltage, 
because it is frequently the case that high copper insertion losses are 
built into such a design. 

The windings surrounding the core have, of necessity, distributed 
capacity across themselves, between themselves, and to the core 
and the case. These capacities are nearly always unequal, that is, 
the effective capacities across the 2 ends of a coil are unlike, which 
in the case of a push-pull transformer will, as the frequency in- 
creases, cause increasingly unequal voltages to be impressed on 



Sept., MM4 COMMUNICATION AND POWER TRANSFORMERS 161$ 

the tube grids. The deviation usually is quite pronounced well 
below the frequency of resonance, and the point at which a measur- 
able difference is found should be taken as the upper limit of the 
range which the transformer can cover. 

The capacitive balance between the windings can be improved 
at least controlled by the introduction of shield windings or 
sheets. Sometimes the shield is connected to a section of the wind- 
ing; more often it is tied to ground. Frequently windings are placed 
in a coil at a place where they act as shield windings because in the 
circuit in which they are used they are connected externally to 
ground. 

When the shield is introduced between the primary and secondary 
windings, and connected to ground, electrostatic shielding is also 



.__- 





FIG. 10. 

obtained, which prevents the transmission of incoming longitudinal 
currents past the barrier thus set up. 

Since magnetic flux is not only in the core, but also linking every 
part of the winding, leakage links are present, causing the induction 
of a lesser voltage in some coils than in others with equal turns. For 
this reason each winding must be symmetrically located with respect 
to the other windings. In the case of a push-pull transformer, both 
secondary windings must cut the same amount of leakage flux, and 
the leakage flux around the start of the primary must be the same 
as the leakage flux around the end of the primary winding. It is 
this leakage flux which does not thread all of the windings of all of 
the coils, that is responsible for the leakage reactance in a trans- 
former, resulting in a drooping response at high frequencies. Many 
transformers have had incorporated in their design just the proper 
amount of leakage reactance to resonate with the high distributed 



164 E. B. HARRISON Vol 43, No. 3 

capacity across the secondary windings at a predetermined high 
frequency. Such a transformer will show an excellent frequency 
response characteristic, but will not have the same time constant 
for all frequencies. Neither will it reflect a constant load to the line. 
These faults can be only partially corrected by secondary loading, 
as a loss of high frequencies is sure to result. 

The windings on each side of a balanced transformer must have 
equal resistance. In the case of a symmetrical coil arrangement this 
usually follows as a matter of course. However, in some designs of a 
special nature where one part of a coil is wound on top of another, 
it may be necessary to change the wire size to accomplish the desired 
result. 



: f r .... r. [.[[ rffp r f f rfi'fff .!* ri'M'i'jii '~ [ f[[[[f 



TBS -|o^ 

: ts^ 4 ". 1*0 TOPOO 



LEVEL -2SS OB 



FIG. 11. 

In the effort to keep the over-all size of a transformer small, very 
fine wires are used in the high-impedance windings. These wires are 
also reduced in size because the spacing between winding layers 
must be large to keep the distributed capacity low. The presence 
of any moisture in the coil or in the paper insulation would seriously 
impair the balance between the coils and the high-frequency response 
of the transformer. This moisture would also facilitate electrolytic 
action between the bare coil ends where they are attached to the lead 
wires. It is necessary, therefore, that the coil be thoroughly desic- 
cated and then sealed. 

This is accomplished by a vacuum impregnation system in which 
the coils are heated under pressure and then maintained in a heated 
condition at a high vacuum from 12 to 16 hr. While still heated and 



Sept., 1944 COMMUNICATION AND POWER TRANSFORMERS 105 

under vacuum the transformers are immersed in a high melting point 
amorphous wax which has been highly refined to remove impurities. 
Pressure is then applied to the surface of the hot fluid wax to force 
it into the coil and between the laminations. The layer paper be- 
comes a framework to support an insulating layer of wax, each in- 
dividual wire is fully coated, and the individual laminations are 
insulated from each other by a coat of wax. The wax chosen for 
this purpose has a low dielectric constant, lower than any of the 
plastic films except polystyrene. It is sufficiently plastic at all oper- 
ating temperatures, even those below zero, to prevent cracking. 
Long life is assured. 

Fig. 8 illustrates an output transformer (TP-204) designed for 
operation between a single-ended or push-pull tube, and a line in the 
range between 20 db and -f 20 db level. Because this rather small 




FIG. 12. 

transformer has to handle large signals, many turns of wire per volt 
of signal were required to keep the flux density low, making it neces- 
sary to lengthen the magnetic path to keep the inductance of the 
windings down to the proper value. In addition, the mean length 
of the copper circuit was kept low to reduce the series resistance in- 
sertion loss. Since the winding length was quite long, the high-im- 
pedance primary winding was broken up into several pieces to reduce 
the developed voltage per layer, and consequently the effective dis- 
tributed capacity. Under certain conditions of operation the 
magnetic flux leakage near the ends of the long legs of the core could 
become great enough to develop an appreciable leakage reactance. 
To prevent this and retain good high-frequency performance the 
tubes surrounding the core, and on which the coils are wound, have 
built into them an eddy current shield, consisting of a single wrap 
of heavy sheet copper with an overlapped, insulated high reluctance 
joint (Fig. 8A). 



166 



E. B. HARRISON 



Vol 43, No. 3 



The astatically balanced construction also reduces external hum 
pickup which is down about 30 db from an uncased shell-type design 
of corresponding size. The entire unit is potted in a 3-section case 
which provides an additional 30 db of shielding. The performance 
of this transformer over a wide range of operating levels is shown 
in Fig. 9. 

Fig. 10 illustrates a small input transformer (TBB-102) designed 
for operation at a 35 db level. The response measured at 22 db 
and 65 db is shown in Fig. 11. A core was chosen with a very short 
magnetic path and with lap joints located near the center of the 
coil structure. A large core area was chosen to keep the operating 




FIG. 13. 



flux densities at low values: of the order of gausses rather than 
hundreds of gausses. The choice of core permitted the winding of a 
small-size coil which even with its small spacing between layers has 
a low distributed capacity. The thickness of the laminations chosen 
allows the development of a small quantity of eddy current which, 
acting on this short magnetic length core, effectively limits the high- 
frequency inductance of the windings, permitting excellent low- 
frequency response at low core densities without objectionably re- 
ducing the high-frequency response. Sheet copper shielding is used 
between the primary and the secondary windings, and is so spaced 
in the coil structure that the capacities from both ends of every coil 
to ground are equal. 



Sept., 1944 COMMUNICATION AND POWER TRANSFORMERS 167 

A transformer of this sort with its high operating impedances, 
in this instance 70,000 ohms, and its consequent sensitivity to ex- 
ternal fields, needs adequate shielding. For this purpose the trans- 
former is cased in a seamless, drawn, round can of high permeability 
alloy. Surrounding this high permeability can is a heavy short- 
circuiting turn of copper. This assembly goes into another can of 
high permeability alloy surrounded by copper, and finally into 
a third high permeability can. Fig. 12 is an exploded view of the 
assembly, which is then vacuum impregnated and potted in its pro- 
tective case. This type of shielding is good for about 30 db per can 
of high permeability alloy, the entire assembly attenuating external 
fields about 90 db. 

A companion interstage transformer has been developed with the 
same characteristics and size as the transformer illustrated. It is de- 
signed to operate single ended or push-pull between 10,000 and 
40,000 ohms. 

Fig. 13 shows the frequency response characteristic of a trans- 
former which is an outstanding example of wide frequency range and 
excellent balance combined with light weight. It is designed for 
operation at 10 db to zero level, has electrostatic shielding between 
the primary and secondary windings, and is potted within a 30 db 
shield can. Excellent high-frequency balance is obtained across the 
2 halves of the secondary, being less than 1 per cent at 55,000 cycles, 
and only 2 per cent at 60,000 cycles. No unbalance at lower fre- 
quencies is measurable. The transformer is potted in a case ! 3 / 4 X 
! 3 /4 X 2 3 /4 in. and weighs 10 oz. 



THE DUPLEX LOUDSPEAKER 5 

JAMES B. LANSING** 



Summary. The Duplex Loudspeaker is a combined two-way loudspeaker 
mounted in an integral unit so that the high-frequency energy is radiated from a small 
multicellular horn mounted on the face of the low-frequency diaphragm. 

Separate permanent magnets of 'improved magnetic material are now used for the 
fields of each voice coil. 

The crossover has been selected at 1200 cycles so that the high-frequency horn can be 
placed in the center of the low-frequency diaphragm. 

A signal input up to 25 w can safely be applied to the speaker. The inter modula- 
tion products are very low as a result of the two-way principle. The configuration 
of the high-frequency horn produces an angle of radiation which is 60 degrees in the 
horizontal plane and 40 degrees in the vertical plane. Due to the type of construction 
a high degree of uniformity between units can be maintained in manufacture. 

The unit is capable of efficient radiation beyond 15,000 cycles. 



The practical application of the Two-Way Multicellular Loud- 
speaker System for theater use began in 1935. Since that time 
there has been a gradual improvement in its quality and general per- 
formance. The wide acceptance of the high performance standard 
set by this two-way loudspeaker system indicated that the benefits 
to be realized by applying the same principles to loudspeakers for re- 
cording, monitoring, and broadcast radio work would be considerable. 

Since the large size of the theater system (Fig. 1) precluded its 
use in monitoring booths, the immediate requirement was that a 
substitute be found for the large folded horn used for the low-fre- 
quency band. Reduction in the size of the low-frequency horn 
called for a corresponding decrease in the size of the high-frequency 
horn in order to make the whole equipment compact. 

The first development to meet these requirements for a smaller 
system made use of a 500-cycle crossover network and a high-fre- 
quency horn designed to give proper acoustic loading at crossover. 

f 
* Presented Oct. 20, 1943, at the Technical Conference in Hollywood. 

** Altec Lansing Corporation, Hollywood. 

168 



THE DUPLEX LOUDSPEAKER 169 

The folded-type horn, much reduced in size, using a 15-in. speaker 
was retained for the low-frequency end. While this design had ade- 
quate frequency range for most small rooms and is being used in 
large numbers by our armed services, it was still too bulky for the 
"cubbyhole" type monitoring room. The effect of separate sources 
for the different frequency bands was annoying when used in close 
quarters. 







FIG. 1. 



In 1937, the first two-way loudspeakers using the multicellular 
high-frequency horn in conjunction with a resonated low-frequency 
baffle were made available under the name of Iconic Loudspeakers 
(Fig. 2). A crossover frequency of 800 cycles was used with a cor- 
responding decrease in the size of the high : frequency horn, com- 
pared to that used with the 500-cycle crossover systems. These 
loudspeakers were far more compact than those using horns of various 
configurations for the low-frequency band. Operating efficiency, 
while not as high as in the larger systems, was still high when con- 
sideration was given to the decrease in size. 



170 



J. B. LANSING 



Vol 48, No. 3 



During 1941, intensive work was undertaken to find a method of 
producing a loudspeaker of still more compact form, retaining the 
same performance characteristics of the larger systems, and at the 
same time totally eliminating the tendency to radiate from split 
sources when used in close quarters. 

The intermodulation .distortion effects produced by a single dia- 
phragm, when operating at a multiplicity of frequencies simultane- 
ously, precluded the use of a single diaphragm for all frequencies. 1 

A metal diaphragm designed 
to operate as a piston up to 
frequencies above the limits of 
audibility, was chosen for the 
high-frequency reproducing sys- 
tem. Aluminum alloy was used 
because of its high mass stiffness 
and high velocity of transmis- 
sion. The resulting lightweight 
diaphragm is stiff enough to 
prevent its breaking up as a 
piston and thus introducing the 
intermodulation effects so com- 
mon to the familiar paper and 
other fibrous types of dia- 
phragms. 

Careful consideration was 
given to the type of high-fre- 
quency radiation system to be 
used. If the diaphragm was 
to radiate directly and was 
made small enough to avoid sharp beam effects at high fre- 
quencies, it became too sinall to handle enough power, near the 
crossover region, for practical purposes. Accordingly, the multi- 
cellular type high-frequency horn was chosen as the radiating medium. 
The final design for the high-frequency horn was a 2 X 3 configura- 
tion of G cells, with a 900-cycle cutoff, which could be enclosed by the 
low-frequency cone. The maximum angle of horizontal distribution 
was held to approximately (JO degrees in order to prevent interference 
from the mounting baffle at the high frequencies. 

Fig. 3 is a cross-sectional view of the completed Duplex .Loud- 
Speaker showing the arrangement of the functional parts in their 




FIG. 2. 



Sept., 1044 



TIIK DUPLEX LOUDSPEAKER 



proper relation. The high-frequency horn is shown mounted on the 
end of the low-frequency unit pole piece, which is bored out to permit 
the passage of sound from the high-frequency unit. A fine mesh 
bronze screen at the junction of the pole pieces prevents the en- 
trance of foreign particles into the high-frequency sound chamber. 
Positive alignment of the bores of the 2 pole pieces and of the horn 
mounting flange avoids discontinuities which would cause destructive 
interference along the high-frequency sound transmission path. 

The high-frequency horn is covered with a sound deadening ma- 




Fiu. 3. 



terial, but is not finished with a smooth surface which would set up a 
regular reflection pattern for sounds being generated by the surround- 
ing low-frequency cone. The dome-shaped high-frequency dia- 
phragm is shown in place over its transducer, which effectively pre- 
vents destructive interference from being set up in the sound chamber. 
The high-frequency voice coil is wound with aluminum wire to hold 
the mass of the moving system to a minimum. The low-frequency 
system consists of a 15-in. paper cone with its actuating motor system 
and surrounding mechanical structure. 

A frequency dividing network of the constant impedance type is 
used with a crossover frequency of 1200 cycles (Fig. 4). The selec- 
tion of the 1200-cycle crossover point permits the 900-cycle cutoff 



172 



J. B. LANSING 



Vol 43, No. 3 



horn to adequately load the high-frequency unit down to a frequency 
where it transmits little power. This eliminates any tendency to 
produce the distortion effects which would be caused if the acoustic 
loading were to cut off sharply at crossover, and effectively prevents 
any damage to the high-frequency unit because of unloading when 
the maximum rating power is applied in the crossover region. 

Fig. 5 shows the Duplex Loudspeaker and its dividing network. 
These networks use iron cored reactors capable of being operated 
over a wide voltage range with negligible change in their inductance 



2.2 M H MATCHING 




-r p A K i c "I 




O, r / A7W7WAAA \ -. "*' i 






8. MFD 8j 2ohms 


TO LOW 
FREQ. UNIT 


IN 


,^_ ^ fi^k^c 








O 




O 3chms 






n. 






1| [ 


o 




R 2.2 MH >, 


-j TO HIGH 




1 > 


FREQ. UNIT 




8. || MFD. 1 1 


L-o 



CROSSOVER =1200 




Z (iN) = !2 OHMS 





FIG. 4. 



value. The networks are not affected by their proximity to other 
apparatus. The assembly shown has been used with various shapes 
and sizes of resonated baffles, but most satisfactory results have 
been achieved when a baffle with a volume of 6 to 9 cu ft was used. 
A 6-cu ft baffle when properly ported* will permit good response down 
to 60 cycles. A 9-cu ft baffle will permit good response down to 



* The port is used to allow the energy which is radiated from the rear of the 
cone to be admitted out the front side in phase with that portion of the energy 
coming from the front of the cone. The effect is to maintain a more constant 
acoustic impedance down to the cutoff of the enclosure. The area of the port is 
a function of the size of the box enclosure and the mechanical resonance of the 
loudspeaker unit. 



Sept., 1944 THE DUPLEX LOUDSPEAKER 173 

approximately 40 cycles. Care must be taken in the construction of 
the baffle to prevent "breathing" effects from the pressures built up 
in it at the lower frequencies. The inner wall of the baffles must be 
covered with sound absorbent material in order to prevent reflections 
which would give a "hang-over" or "echo" effect. 

Comparative tests of the Duplex Loudspeaker with the larger sys- 
tems have been highly satisfactory as to reproducing characteristics 
and efficiency. At a distance of 2 ft from the new unit, all fre- 
quencies being reproduced appeared to come from a single source. 
The high-frequency radiation angle of 60 degrees by 40 degrees is 
small enough to avoid reflections from the baffle as the sound leaves 




FIG. 5. 

the high-frequency horn, but is still ample to permit the listener to 
move about with considerable freedom. 

The uniform characteristics which can be maintained from unit to 
unit should make the Duplex Loudspeaker ideal as a monitoring 
standard. The elimination of vertical spacing between the source 
of high frequencies and the source of low frequencies brings about a 
point source of reproduction which is found to be very realistic and 
helpful in the critical judgment of quality. 

REFERENCE f 

1 BEERS, G. L., AND BELAR, H.: "Frequency Modulation in Loudspeakers," 
/. Soc. Mot. Pict. Eng , XL (Apr., 1943), p. 207. 



SIXTEEN-MM COLOR TO 35-MM BLACK-AND-WHITE* 
CARROLL H. DUNNING** 

Summary. -Because of the increasing interest in the enlargement of "blow-up" 
of 16- mm to 35-mm, this paper offers some timely "do's and "don't's" taken from 
practical experience. 

Newsreels often show scenes of heroic rescues, aerial blitzes, 
and other "on-the-spot" thrillers. Sometimes the photography is 
noticeably bad, lighting is poor, focus hazy and grain size most 
annoying. 

Probably they were photographed originally in 16-mm black-and- 
white and then blown up for theatrical release. 

I have never felt, however, that a cameraman on a tossing ship 
in a stormy sea should be severely criticized for not resetting his 
focus between bursts from a diving Stuka. 

In studio photography, "Oscars" are won with the slight as- 
sistance of "gaffers," "juicers," "key-lighting," "baby spots,' 1 "ears," 
"goboes," assistants, "loaders," "grips" and an easy chair and other 
simple appurtenances. Therefore such vital subject material should 
be viewed from the standpoint of audience interest and not as a yard- 
stick by which to judge the value of 16-mm blow-ups. 

It seems rather paradoxical to suggest the use of K)-mm color 
originals for ultimate 35-mm black-and-white results, but the reason 
is quite apparent. Kodachrome, as an example, is a dye product. It 
contains no silver. Therefore, the problem of grain magnification is 
eliminated. 

Another impelling reason for the use of Kodachrome originals is 
the opportunity it affords for selective alteration of contrast in the 
35-mm negative produced therefrom. For example, the coloration 
of live actors in a scene is naturally on the red end of the spectrum, 
while sky and foliage are generally complementary in hue and tone. 
Thfe sky may be overemphasized in deep blue when photographed 

* Presented Oct. 21, 1943, at the Technical Conference in Hollywood. 
** President, Dunningcolor Corporation, Hollywood. 
174 



SIXTEEN-MM COLOR TO 35-MM BLACK-AND-WHITE 175 

opposite the sun, and particularly in aerial shots photographed ap- 
proaching the zenith. When enlarging under these conditions the 
use of a compensating filter within the blue range will suppress the 
complementary reddish ness of the faces, and allow a greater over- 
all exposure to be used on the 'J.Vmm negative. This will give a 
heavier deposit in the sky portions of the negative without increasing 
the negative weight of the faces. The final black-and-white positive 
will then have a normal gray sky instead of black, and the over-all 
values will be more nearly in balance. 

On the other hand, if confronted with a flat, yet properly exposed 
desert scene with light skies, dun-colored earth, and filled with 
soldiers in khaki, you have an over-all reddish characteristic. You 
can increase the contrast of this original by the use of the same series 
of complementary compensating filters. 

Conversely, the over-all contrast can be lowered by using compen- 
sating filters in the same tonal range as the over-all characteristic of 
the scene. 

An alternative, of course, for altering over-all contrast may be 
attained by varying the time period of negative development. 

Amateurs have turned in a wealth of material, some beautiful and 
some! They have shot with pockette cameras, magazine loads and 
daylight loads, all very satisfactory for their needs. These individual 
magazines having their own positioned apertures are at best made only 
of stamped metal and the aperture does not always accurately co- 
incide with the static position of the pull-down pins in the camera 
to which it is attached. But if Kodachrome is to be used for copy 
enlargement it is imperative that the photographed frame line be 
centered across each set of perforations. 

Naturally an optical printer is a precision instrument and is lined 
up to enlarge each 16-mm frame having a picture field bounded top 
and bottom by frame lines centered across the pairs of perforations 
in the original. If these vary from scene to scene as they often do, 
then they will be reproduced in the enlarged 35-mm blow-up within 
the visual field of the resultant projected image. To limit the field 
to be enlarged to the restricted area within the possible wanderings 
of these frame lines, is about as logical as eating the heart of a water- 
melon and throwing the rest away, and optical printers have no 
automatic means of anticipating this change of frame line in relation 
to perforations from scene to scene. 

The solution simply forego the urge to blow-up everything from 



176 C. H. DUNNING Vol 43, No. 3 

Boulder Dam to baby's first tooth (because it's such a swell shot and 
the president's son took it himself). 

Start with a 16-mm camera that has been tested for standard 
frame-line accuracy, and if this is off standard have the aperture 
repositioned. If you have several magazines, as part of a good 
camera equipment, test all of them. Hire a cameraman of proved 
ability in the 16-mm color field. Insist upon the use of needle-sharp 
color corrected lenses. Enlargement does not enhance definition. 
Scenes that are soft focus in character or indifferently sharp, may 
appear satisfactory in the original but their faults may be glaring in 
the blow-up. 

On the exterior shots where controlled lighting is impossible it is 
better, if feasible, to adhere to flat lighting with the sun at your 
back. Remember that color rendition does its own modeling. 

Kodachrome is a fairly short scale medium, and blocked in shadows 
with empty high lights caused by cross and back lighting give an 
effect of unpleasant high contrast in the final black-and-white en- 
largements. 

For interiors, or close-ups, where light sources can be controlled, 
it is not only permissible but effective to accentuate your modeling by 
cross or back lighting, provided your over-all front fill light has defi- 
nitely filled in your shadow detail. 

In all professional photography, your entire effort, worthy or 
otherwise, as well as your investment, is vested in your master nega- 
tive and is guarded as such. Kodachrome originals occupy exactly 
the same position and are likewise the repository of your entire in- 
vestment. But being a reversal process and positive in form there 
seems to be an almost uncontrollable yen to project them "just once" 
you know, just once for the boss. Don't Do It. 

The smallest projection scratches and rewind cinch marks are mag- 
nified about 6 times their size on the enlarged 35-mm negative, and 
the refractive characteristic of a scratch even increases the ratio. 

The safe and satisfactory procedure is to make a duplicate Koda- 
chrome print of your "dailies" immediately. Then when you have 
edited the latter and eliminated all definitely unusable sequences, 
you can conform your original and blow-up the sequences which 
may possibly appear in the picture. 

There are many advantages in the use of 16-mm Kodachrome. 
The photographic equipment is light in weight and its smaller size 
makes it extremely practical in confined spaces. Further, the ease of 



Sept., 1944 SIXTEEN-MM COLOR TO 35-MM BLACK-AND-WHITE 177 

handling as against a more cumbersome equipment make it ideal in 
many situations. For example, a follow shot of a bomb released 
through the bomb bay door of a plane, or a remote control shot from 
the rear of a P38, and for atmosphere or "pick-up" shots the 16-mm 
camera is unexcelled. The public simply accepts it as a common- 
place amateur instrument and does not realize that you are making 
movies. 

As I said before, there is no grain size to be enlarged, for Koda- 
chrome is grainless. And the selective alteration of contrast is an 
attractive factor. In these wartimes, good 16-mm equipment is 
scarce, but wars will end. \ 

In view of the fact that Kodachrome had its first success in the 
realms of "you press the button we do the rest," we are apt to be- 
little its unquestioned and varied uses in the professional field. 

Kodachrome 's history has almost paralleled the course of radio, 
but remember radio passed through the growing pains of crystal sets 
in the hands of amateurs and now look at the darn thing! 



WHAT TO EXPECT OF DIRECT 16-MM* 
LLOYD THOMPSON** 

Summary. People who are using direct 16-mm productions for the first time, 
or those thinking of using them, will naturally have a lot of questions to ask about the 
method. They will want to know the advantages of the system, what can be done in the 
way of photography and sound, and what production and laboratory facilities are 
available. They will also want to know what may be expected of the final product in 
this field. The following paper will consider these questions and state what may 
be expected of direct 16-mm as it is known today. 

The advantages of making pictures by the direct 16-mm method 
have been discussed before this Society and in various publications 
from time to time. Producers have not always been able to profit 
from these advantages because some of the services needed or some of 
the equipment required have not been generally available, but im- 
provements are correcting this situation. 

There seems to be an opinion that in a few years all the pictures 
made in the* industrial field and most entertainment films will be shot 
on direct 16-mm. The individuals closest to the 16-mm industry 
think that direct 16-mm is going to play an ever-increasing role in 
certain types of production, but that there are certain places where 
it definitely should not be used. To use this method of production 
where it is not suitable will do the industry more harm than good. 

The following are the general types of motion pictures, but not 
necessarily in order of importance: 

(1) Industrial. 

(2) Educational. 

(3) Entertainment. 

(4) Propaganda. 

Direct 16-mm producers, and many not in this business, think that 
in the future a high percentage of the industrial films will be made 



* Presented Oct. 21, 1943, at the Technical Conference in Hollywood. 
** The Calvin Company, Kansas City, Mo. 



178 



WHAT TO EXPECT OF DIRECT 16-MM 179 

by the direct 10- mm method. The distinction between industrial 
films and the other types is very indefinite because such films are 
often also educational, may be entertaining, and may contain propa- 
ganda. In general, they are designed to present special subjects 
to selected audiences, and are not generally released to the public. 
Many of these films are made by professional film producers, but some 
are made by company organizations themselves. 

Many of the thousands of industrial films being made today can 
be classed as educational films, and a number of such films are being 
produced by the U. S. Office of Education as well as by the Army and 
Navy. Many war factories are making films to teach such things as 
indoctrination, safety and operation of machines. A great many of 
these films can be and are being made by the direct 16-mm method. 

There' have been several entertainment films made by the direct 
16-mm method, such as the shorts produced by Warner Bros, a year or 
so ago, and the short sections of the recent Walt Disney film Saludos 
Amigos. These films were produced on 16-mm Kodachrome and later 
enlarged to 35-mm Technicolor. Most people directly connected 
with the direct 16-mm industry do not think that this procedure 
has anything in particular to recommend it, and that a better job 
can be done by the conventional method, except in taking war films 
where 16-mm offers advantages, especially when photographing in 
color. They do think that a few entertainment films can be made 
by this method of production where all of the distribution is to be 
limited to 16-mm. However, as a rule, entertainment films must 
first be made on 35-mm film for the theater because there is not suf- 
ficient demand for 16-mm prints to make it profitable to produce 
good entertainment films by this method. 

Few people like to have their films called propaganda films al- 
though a great number of them listed under other classifications 
should probably be called propaganda. A great many such films 
are made by civic organizations and other groups wishing to promote 
some special plan or idea. Since such groups usually do not have a 
great deal of money to spend, an ever-increasing number of such 
films are made by the direct 16-mm method. 

Some of the things the prospective user of 16-mm films may ask is 
whether they can be made in black-and-white or color, whether they 
must be silent or can have sound, or whether sound can be added to 
silent color films. The answer to all of these questions is "yes." 

Synchronous sound with dialogue or sound effects can be used, or 



180 L. THOMPSON Vol 43, No. 3 

the picture can be shot as a silent "show" and later sound effects, 
narration, and music added. The prospective user of a direct 16-mm 
production may be interested in making his own show, or he may be 
interested in letting some commercial producer make the show for 
him. In that case, he will be interested in knowing what production 
facilities are available and just how complete these facilities are for 
direct 16-mm production. There are commercial organizations set 
up to do direct 16-mm work whose services include practically every- 
thing which can be obtained from any industrial organization working 
in 35-mm. If the user of direct 16-mm film wishes, he may turn his 
entire production over to one of these organizations and they will do 
the entire job from script to finished projection print in black-and- 
white or color, with sound. 

What does such an organization have to offer? First, there is 
the sales department. As a rule, this part of the organization is tied 
together very closely with the chief director. After the show has 
been sold, the chief director works with the client in order to deter- 
mine exactly what is to go into the show. After this has been deter- 
mined, the chief director then gives the specifications to the produc- 
tion director, who with the camera crew starts working on it. 

There are sound stages as large as some in Hollywood studios, 
where the pictures may be shot in synchronous sound or as silent 
shows with sound added later. Such studios are equipped with 
camera dollies, professional 16-mm. cameras, professional lighting 
equipment such as Mole-Richardson, and where sets are built as they 
would be on a Hollywood stage but usually not as elaborate. 

Complete laboratory facilities are maintained for developing black- 
and-white reversal films, sound tracks, work prints, and release prints. 
All work on color films is done except developing which is still per- 
formed by the manufacturer. 

Production facilities include script writers, editing rooms, editors, 
cutters, printers for adding special transitional effects, recording 
facilities for working on 16-mm film or acetate disks, recording 
facilities for blending music, voice, and sound-effect tracks into a 
final printing track ; an art department for making special titles, and 
an animation department for doing animation work in either black- 
and-white or color. To my knowledge, there is only one organization 
that has all of these facilities within one organization and that is 
The Calvin Company. However, any of the direct 16-mm produc- 
ers who so desire can purchase any of the services which he is not 






Sept., 1944 WHAT TO EXPECT OF DIRECT 16-MM 181 

able to perform himself. Naturally, there are not as many direct 
16-mm producers who are as completely equipped as there are 35-mm 
producers. 

The prospective user of direct 16-mm productions may desire to 
make his own show or a part of it, and then avail himself of certain 
services such as sound recording, editing, and perhaps laboratory 
facilities. Just as in the case of the producer who does not own all 
of his equipment, the user doing his own show can purchase any of 
these items. 

Direct 16-mm photography which is to be printed and shown as 
16-mm can be as good as, and in some cases better than, 35-mm 
which has been reduced to sixteen in either black-and-white or color. 
Naturally, this does not mean that all 16-mm photography is good 
because there is a lot which is not. On the other hand, there is a lot 
of 35-mm photography which is not good. If good results are to be 
expected from either method of production, certain definite rules 
must be followed. The people doing the photography must under- 
stand the problems if the best results are to be obtained. Owing to 
the shorter length of lenses used on 16-mm to cover the same area, 
it is sometimes possible to shoot certain scenes with less light and still 
obtain the same depth of field. However, too many people have the 
idea that because they are shooting 16-mm they can use amateur 
lighting equipment, and in much less quantities than any professional 
shooting 35-mm would think of using. This is not the case. 

If good results are to be expected, scenes must be properly lighted 
and there must be plenty of light available in order to have properly 
exposed film. Direct, 16-mm production does offer distinct advan- 
tages in shooting color. Kodachrome film is balanced for photo- 
flood illumination, therefore it is possible to get considerably more 
light without overloading lines, an important factor in industrial 
production. 

The larger the appropriation for producing a show, the less im- 
portant becomes the cost of the raw stock necessary, but a high per- 
centage of the shows suitable for direct 16-mm production is made 
on limited budgets, and in such cases the cost of the raw stock, 
transporting it from various parts of the country to the laboratory, 
and other such items, add up to a considerable amount and become 
important items. It has recently been determined that for every 
client who can afford to spend $15,000 to $20,000 in making a show, 
there are eleven more prospects who cannot, and for these people 



182 L. THOMPSON Vol 43, No. 3 

direct 16-mm may be the answer. In such cases a saving of several 
thousand dollars may mean the difference between having a show or 
not having a show. 

Since 16-mm equipment is smaller and lighter in weight, there are 
cases where it can be substituted for the bulkier equipment, resulting 
in an economy in manpower. 

As previously stated, sound for direct 16-mm productions can 
be made as either "sync" sound or off-stage sound. There are a few 
sound shots which are made by the single system method, but the 
serious producers of direct 16-mm use only the double system method 
of making sound. Almost anything which can be made by the 35- 
mm method can be done by direct 16-mm. This does not mean 
that the sound quality of direct 16-mm is as good as the best 35-mm. 
However, it can be as good as 16-mm reduced from the best 35-mm 
sound. Many times we have heard direct 16-mm sound tracks 
which have been better than 35-mm, but in such cases we felt that it 
was due either to a lack in the 35-mm equipment or in the way in 
which it was handled. 

In making direct 16-mm sound, we follow as a rule the most direct 
course possible, such as using direct optical positives to be used for 
printing with Kodachrome thus eliminating one step. Direct 16- 
mm film can be rerecorded, but we do not believe that it can be re- 
recorded 3 or 4 times as is sometimes done with 35-mm. In most 
commercial shows it is not necessary or desirable to do this. A 
method which is gaining some favor for certain synchronous sound 
shots such as sound effects, is to record the original sound on acetate 
disks and then "dub" it off to a sound track. There are also times 
when it is desirable to record shows on disks and transfer to film. 
Many independent workers are finding this more desirable than 
buying film recording equipment. By using this method they can 
hear their results immediately. Where synchronous sound effects 
are desired, this is quite satisfactory and desirable as it eliminates 
certain chances taken during the recording of any synchronous 
sound, especially if it happens to be out of the studio. 

Laboratory service for original reversal picture film in black-and- 
white is pretty well taken care of and standardized. There are 
certain precautions which should be observed, and if this is done 
there are laboratories from coast to coast which can do a good job 
with the original photography. 

As yet there are comparatively few laboratories that are able to 



Sept., 1944 WHAT TO EXPECT OF DIRECT 16-MM 183 

develop sound tracks, make reversal prints, dupe negatives, positive 
prints from dupe negatives and release prints. However, the lack 
in number of laboratories is no serious handicap, because if fast 
service is wanted, air express can be used and at least one of these 
laboratories can be reached overnight from almost any point in the 
United States. 

The production of large numbers of release prints from direct 
16-mm originals at low cost is still one of the biggest problems of the 
industry. So far the cost of good prints from 16-mm originals has 
been fairly high and the' laboratories producing them have justified 
these high costs as resulting from the extra care and special machinery 
necessary to turn out good work. Also, this machinery has been of a 
type which does not permit fast printing and perhaps this has in- 
creased the cost of release prints more than it should. 

Until recently comparatively few prints have been ordered from 
most 16-mm shows naturally making the print cost higher, but this 
additional print cost has not been serious because of the small number 
of prints generally used. However, the war has changed this situa- 
tion and large numbers of prints are now being made from the original 
films. 

The Calvin Company has been working to correct this release print 
situation so that large numbers of prints can be made in a reasonable 
time and at a cost somewhat less than has been possible in the past. 
A number of special printers have been, or are being, constructed, 
and we have taken over a new building which will be devoted entirely 
to the production and laboratory work of direct 16-mm. Printing 
will be done in filtered air-conditioned rooms, all prints will be de- 
veloped on automatic processing machinery, and all processes will 
be kept under strict control 

To give an example of what this expansion means we will describe 
the method used in printing Kodachrome sound prints with optical 
effects in the photography and sound. In the past it has been neces- 
sary to print this on a special printer at a rather slow speed. It was 
necessary to double print the picture material, taking approximately 
an hour and ten minutes per 400-ft reel to print the photography and 
the sound on each release print. A new high-speed printer has been 
designed for printing the photography with optical effects and a 
sound track in one operation, and it is now possible to print a com- 
plete 400-ft reel in approximately 6*/2 min. 

The printer will be practically automatic in operation and will run 



184 L. THOMPSON Vol 43, No. 3 

in both directions. It will only be necessary for the operator to 
thread raw stock in at the end of each reel, turn it on and wait for it 
to stop, and then thread it with fresh stock again. Once the printer 
is set up to operate like this, all the light changes will be made auto- 
matically with absolutely no chance for error, and thus a great many 
color sound prints with optical effects can be turned out in a very 
short time. The printers are capable of handling 1200 ft or 3 reels 
at one time, thus the average 16-mm show can be printed in one con- 
tinuous length. 

We have already said that the relatively high cost of good 16-mm 
prints has worked against the direct 16-mm idea somewhat. Another 
disadvantage of the direct 16-mm process has been the slowness with 
which release prints could be made. There have been 2 reasons for 
this: The laboratories in a position to make good 16-mm prints 
have been swamped for about 3 years, and their printers have been 
too slow and too limited in number. 

In the new setup which The Calvin Company is making it is our 
desire to eliminate this particular bottleneck, and we expect to be able 
to deliver large numbers of high-quality prints in a very short time. 
It is not necessary that this be done on all shows, but there are many 
times when some large national concern wishes to release a picture 
over the entire territory at one time. In such cases it is very neces- 
sary that a large number of high-quality prints be released within a 
few days after the first print has been approved. 

Naturally these services will first be used by the Armed Forces and 
other governmental agencies producing 16-mm films, but it is believed 
that before too long a certain percentage of these facilities will be 
available for private industry and other producers. At the present 
time, the facilities are available only after high priority work is com- 
pleted. 

After the show has been completed, the owner will then want to 
know what kind of projection equipment he should use, and what 
kind of equipment is available. In this field he has an almost un- 
limited choice, practically all of it much more portable than any 35- 
mm equipment. If the show is to be exhibited to only a few people, 
say, 10 or 15 at a time, the Movie-Mite projector can be used very 
successfully. This is a machine which weighs only 24 Ib, has a 200- 
w projection lamp, -and has ample sound volume to use with an 
audience of 30 or 40 people. This machine is extremely portable and 
carries a speaker and screen in the same case, with the amplifier and 



Sept., 1944 WHAT TO EXPECT OF DIRECT 16-MM 185 

projector. It sells at a low cost and is especially suitable for shows 
in individual offices or homes. 

On the other hand, if it is desired to exhibit before a larger group, 
say, from 50 to 200 people, the exhibitor can use one of the conven- 
tional sound projectors on the market such as Bell & Howell, Ampro, 
Victor, or Eastman. These come in various models and usually have 
750 -w lights and an amplifier with a power of approximately 6 to 15 w. 

If the exhibitor wishes to project before more people than the con- 
ventional-size machine can successfully handle, he may go to the Bell 
& Howell 1200-w projector which fills a much larger screen. This 
machine has a great deal more power in the amplifier, and when used 
with one of the better types of speakers it will give excellent sound 
reproduction. 

The exhibitor may wish to project before 1000 or more people, in 
which case several arc lamp projectors are available with which it is 
possible to cover an average-size theater screen. A high-quality am- 
plifier system is available with .this unit, with excellent sound re- 
production. 

With this excellent choice of 16-mm sound projectors, a very flexible 
program for exhibiting direct 16-mm films or any 16-mm film can be 
easily arranged, and the projection can be tailored to suit the audience 
group. 

The 16-mm camera and projector were developed in order that 
more people might enjoy and use motion pictures. The direct 16-mm 
method of production has been developed in order that more people 
may enjoy the benefits derived from the use of motion pictures. 

DISCUSSION 

MR. SLYFIELD: Which do you consider better for 16-mm Kodachrome prints 
variable-density or variable-area sound tracks? 

MR. THOMPSON: Our experience has been pretty largely confined to variable 
area as nearly all of the 16-mm recorders available are using the variable-area 
method. When properly made, and properly controlled, we feel that either 
method is capable of giving excellent results. There are bound to be some 
differences in printing and processing Kodachrome sound tracks from, day to day, 
and we believe that the variable-area methods give more latitude in this respect 
without harmful effects on the sound track than the variable-density method. 
Kodachrome is a reversal process and we know from experience that in printing 
black-and-white reversal prints we have considerably more latitude with variable 
area than we do with variable density. I might also mention that all of our 
tracks have beeji developed in Kodak laboratories where the sound track is given 



186 L. THOMPSON 

special treatment. If this is not done, variable-area tracks on Kodachrome are 
unsatisfactory. 

MR. WOLFE: In its Hollywood plant, RCA has employed both variable-den- 
sity and variable-area recording on 16-mm film. In general it has been our 
experience that the differences in quality which exist on 35-mm film between 
these 2 recording systems also exist on 16-mm film thus either system is capable 
of providing a commercially satisfactory job. Under normal circumstances, we 
employ variable area although special conditions involved in the processing of 
color prints have shown preferences. Under some conditions, better results 
have been obtained with variable-density recording, and under other conditions 
better results have been obtained with variable-area recording. 



A RERECORDING CONSOLE, ASSOCIATED CIRCUITS, 
AND CONSTANT B EQUALIZERS* 



WESLEY C. MILLER AND HARRY R. KIMBALL*' 



Summary. This paper describes a two-position console developed to handle multi- 
track rerecording requirements using sliding volume controls and pre-set equalization 
with which the mixer has at his command combinations of equalizers that may be con- 
nected into the circuit upon cue as required. 

Also a variable-type attenuation equalizer circuit, arranged to give improved equal- 
ization characteristics as the control dial is varied from step to step, is discussed. 

The demands upon the rerecording equipment at Metro-Goldwyn- 
Mayer Studios have been growing since the inception of sound on 
film. This is the result of normal factors accompanying any healthy 
industry, such as growth, and change in techniques to improve the 
product. At various instances in the past improvements have been 
made in the kinds and amounts of equipments available for our re- 
recording purposes, but these of necessity have mostly been of the 
nature of additions to existing equipments. 

Shortly before the present war, work was started to engineer al- 
most completely new rerecording equipment, primarily to provide 
expanded facilities, but also offering an opportunity to secure a re- 
recording plant incorporating the results of our experiences as to the 
type and amount needed. 

This paper describes the salient features of a rerecording console 
and associated electrical network circuits provided in connection 
with this project. Emphasis is placed upon the features that are 
new to the industry. 

Rerecording requirements at Metro-Goldwyn-Mayer Studios 
have developed in such a manner that more sound tracks are generally 
involved than is the case in many of the other studios. The average 
number of tracks is about 8, but sometimes as many as 15 or 20 tracks 
may be used. It is the policy at this studio to handle these tracks 
with one mixer most of the time with a second mixer to help out 

* Presented Apr. 17, 1944, at the Technical Conference in New York. 
** Sound Dept., Metro-Goldwyn-Mayer Studios, Culver City, Calif. 

187 



188 



W. C. MILLER AND H. R. KIMBALL 



Vol 43, No. 3 



on the more complicated jobs. This is not especially a matter of 
economy but rather to realize on the advantages to be gained by 
concentrating the controls in the hands of a limited number of people. 
Therefore, a fundamental requirement of the rerecording facilities is 
that they should be as simple to handle as possible so that the mixer 
may give a minimum of attention to the mechanics of his work, 
and devote most of his efforts toward accomplishing the dramatic 
effects desired. Where rerecording equipments are awkward to 
operate, or are not sufficiently flexible in their patching arrange- 
ments, the mixer is unduly handicapped in accomplishing his dramatic 
objectives. 




FIG. 1. Front view of rerecording console. 

The mixer console and associated network equipment described 
herein reflect our experiences in providing adequate mixer facilities 
so far as we are able to engineer and supply them at the present 
time. 

It is proper to point out that the future o*f rerecording will un- 
doubtedly provide for the automatic control, and repetition for re- 
hearsal purposes, of the many things which the mixer has to do. 
Without attempting for the present the solution of the detailed 
mechanical and electrical problems, the ultimate rerecording system 
should provide means for making a progressive record of everything 
the mixer does, so that for each successive rehearsal the equipment 
adjustments used throughout the previous rehearsal will be auto- 
matically repeated. With such measures available his work during 



Sept., 1944 RERECORDING CONSOLE, CIRCUITS, AND EQUALIZERS 189 

a rehearsal and the final recording will be of a "touch up" nature 
rather than a complete repetition of all the previous equipment 
adjustments, leaving him free to concentrate on quality and dramatic 
requirements. 

The exact pattern this development will take is not yet clear, but 
in the design of the Metro-Gold wyn-M ay er console every attempt 
has been made to anticipate the adaptations which might be required 
and to provide for their later inclusion to the maximum practicable 
extent. In general, such a system might well involve having nothing 



1 




FIG. 2. Front view of rerecording console showing master mixer position. 

but controls in the console, with all the voice equipment mounted in 
another location. 

General Console Features. The particular design which has been 
adopted for the console is shown in Figs. 1 to 5, inclusive. The con- 
sole is arranged for operation by two mixers when necessary, and 
following our usual practice the left-hand side is the master posi- 
tion; that is, the position used when only one mixer is working, or 
when one mixer is in charge of an assignment involving two men. 

The volume controls are placed on the slightly sloping surface in 
front of the mixer, and the network controls are arranged in semi- 
circular banks facing the mixer positions. Following our customary 
practice these equipments are so placed that the volume controls, for 



190 



W. C. MILLER AND H. R. KIMBALL 



Vol 43, No. 3 



the master position, are operated by the right hand and the network 
controls are operated by the left hand. The reverse procedure, of 
course, applies for the right-hand or secondary mixer position. A 
volume indicating meter and limiter indicator are in front of each 
mixer. The squeeze mat indicator is in front of the master mixer only, 
and is controlled by him by means of a foot pedal. 

The console table itself is, in effect, a mounting frame for various 
equipment elements. It is kept low in height to permit good vision 
to the screen and to avoid acoustic pockets. The sides, top and back 




FIG. 3. Front view of rerecording console showing foot controls. 



are removable for installation and maintenance purposes. All ap- 
paratus mounted in the console is of unit-type construction, complete 
in itself including controls. The units are physically arranged to 
allow sliding into the proper position with their controls within easy 
reach of the mixer. Specialized mounting arrangements are avoided 
by using the same type of mounting framework for each apparatus 
unit. This construction is excellent from the standpoint of original 
installation as the complete console is assembled and wired by the 
manufacturer and its installation is a matter of connecting external 
trunks to terminal blocks and mounting and connecting unit pieces 
of apparatus. The unit-type construction for the equipments also 



Sept., 1944 RERECORDING CONSOLE, CIRCUITS, AND EQUALIZERS 191 

facilitates maintenance replacements which can be made quickly 
when touble develops. 

Ten volume controls are placed in front of each mixer position mak- 
ing a total of 20 sound tracks which can be handled without employing 
auxiliary facilities. These controls, as contrasted with the usual 
rotating type, are of the sliding up and down controlled-type used by 
our studio for many years. This control movement is an important 
feature as it gives the mixer a certainty and dexterity of control un- 
known to mixers familiar only with the rotating type of volume 




_ i 



FIG. 4. Rear view of rerecording console. 



control. Much time and effort has been expended in developing this 
fader. The volume control assemblies are also of unit- type construc- 
tion, 2 attenuators to a unit. The units are easily removed and re- 
placed by spares. 1 

Patching jacks of the single-plug type appear on the console mid- 
way between the two mixer positions and within reach of either mixer. 
These are shown in the figures. In order to avoid using more jack 
space in the front of the board than necessary, the jack positions of 
secondary importance were located in the back of the console where 
patching can also be made when necessary. 

The figures also show a fader control position at one end of the 



192 



W. C. MILLER AND H. R. KIMBALL 



Vol 43, No. 3 



console. It is common practice to use the same room interchange- 
ably for rerecording and for review purposes. The fader control posi- 
tion facilitates this interchangeable use. 

The Console Circuit. The basic circuit for the console is shown 
in Fig. 6. It is arranged to connect to incoming or outgoing circuits 
of 200 ohms impedance. Equipment patching points are provided 
at a number of places within the circuit to permit the insertion of 
apparatus, such as equalizers, when needed. All apparatus patched 
into the console circuit is likewise designed for 200 ohms image 




FIG. 5. Rear of refecording console with cover panels removed. 

impedances. The patching points permit the inserting of apparatus 
to affect the signals of the incoming circuits in groups of one, two, 
four, or the total of circuits. This has been found to be a practical 
setup for the rerecording work of our studios. It affords a maximum 
of flexibility in the use of patched in apparatus, but, more impor- 
tant, the mixer is able to use variable networks with groups of 
sound tracks thus reducing his mechanical work. 

The patching points are obtained by the use of the transformers 
shown which are known as mixer transformers. This transformer is 
an extended design of the well-known hybrid coil, the revised design 
of which was developed at Metro-Goldwyn-Mayer Studios for our 



Sept., 1944 RERECORDING CONSOLE, CIRCUITS, AND EQUALIZERS 193 

mixer purposes. By its use any number of incoming circuits in 
multiples of two can be effectively joined together on a matched im- 
pedance basis with a minimum of transmission loss to form one 
outgoing circuit, or conversely. More information is given later 
concerning the design of this transformer for multicircuit use. 

The basic console circuit has a transmission loss of about 23 db. 
This is divided among the circuit parts as follows : The volume con- 
trols used are of the slide-wire type having a minimum loss of about 
6 db. Each of the two-position mixer transformers has a theoretical 




FIG. 6. Basic console mixer circuit. 

loss of 3 db, or an actual loss of about 4 db. This makes 8 db for 
2 such coils in any circuit. The six-position mixer coil has a theoreti- 
cal loss of 7.8 db, or an actual loss close to 9 db. 

Electrical Networks. The controls for a variety of electrical net- 
works appear in front of each mixer position as shown in the figures. 
These include variable high and low pass filters, special effects net- 
works, and a generous supply of variable equalizers. Except for the 
equalizers the networks are of conventional design provided with 
controls for step-by-step variation of their insertion loss characteris- 
tics by means of tapped electrical elements. The variable equalizer 
networks, called Constant B Equalizers, were specially designed in 



194 



W. C. MILLER AND H. R. KIMBALL 



Vol 43, No. 3 



connection with the provision of these new facilities to give greatly 
improved variable equalization characteristics and control features 
over our past supply of such networks. Being of a design new to 
the industry engineering information concerning them is given later 
on in this paper. 

Pre-set Circuit. Another feature of the console which is proving 
of great value is' a circuit called a Pre-set Circuit shown diagram- 
matically in Fig. 7. A large number of the variable equalizers sup- 
plied for the console are "normalled" to the pre-set circuit. This cir- 
cuit as a whole, including its normalled apparatus, may be patched 
into any one of the patching points shown in Fig. 6. Essentially the 
pre-set arrangement allows the pre-setting of banks of equalizer 




FIG. 7. Pre-set circuit. 

equipment for some definite equalization condition and its switching 
into the console circuit at any desired place in a reel of film. Its use 
has reduced the mechanical work of the mixer and freed his atten- 
tion for other things by accomplishing in one movement what might 
have required several with an accompanying diversion of attention. 
The switching controls for the circuit to switch from one pre-set 
condition to another are push buttons appearing on the mixer console 
near the volume controls. Three pre-set conditions and a normal are 
provided with each pre-set circuit, and each mixer position has one 
such circuit. The pre-set buttons for the secondary mixer position 
are multiplied over to the master position for his use when needed. 
The equalizers normalled to the pre-set circuits may be patched out 
and used in other places, if desired, or additional networks may be 
patched into the pre-set circuits by means of the jacks provided. 



Sept., 1944 RERECORDING CONSOLE, CIRCUITS, AND EQUALIZERS 195 

Mixer Transformers. As previously mentioned the mixer trans- 
formers used with the console circuit are an extended design of the 
conventional hybrid coil. Consider the circuit of Fig. 8 A which 
shows an unbalanced hybrid coil in the usual form. For mixer pur- 
poses, a mixer coil is assumed to be one which effectively joins a 
number of ''collecting" circuits to one "receiving" circuit. A match 
of impedances at all points where the circuits join the transformer, 
and a minimum of transmission loss is desired and obtained. For 
the circuit of Fig. 8 A a double winding, that is, windings A and B, 
provided the means for obtaining 2 collecting circuits. We might 
also have put on another pair of these double windings, as shown in 





R2- 






R4 



TWO-POSITION MIXER TRANSFORMER 



FOUR-POSITION MIXER TRANSFORMER 



FIG. 8. Mixer transformers. 



Fig. 8B by windings C and D, and obtained 4 collecting circuits. 
In fact, each time another pair of windings is added 2 more collect- 
ing circuits are made available. A general mixer transformer, then, 
is one which has "n" collecting circuits and "n" associated windings 
with the restriction that the windings and circuits must occur in 
pairs. 

For Fig. 8B the resistors RI, R2, Rs, and R 4 represent 4 collecting 
circuits. The resistors RI and R 2 form a pair of such circuits, and 
R 3 and R4 form another pair. The circuit resistances of any pair of 
collecting circuits must both be alike, but the impedances of the pairs 
may differ among themselves providing the design takes this con- 
dition into account. However, for this paper it is assumed that the 
resistances of the collecting circuits and the receiving circuit are all 



196 W. C. MILLER AND H. R. KIMBALL Vol 43, No. 3 

alike and equal to R ohms. In other words, the console mixer cir- 
cuit maintains a constant resistance of R ohms throughout. 

The resistors R B provide the means for obtaining matched im- 
pedances at the circuit connecting points. For "n" collecting cir- 
cuits having impedances of R ohms, all the R B resistors are alike and 
have the following value : . 



RB = Ro 



The transmission losses among the different circuits connected to 
the mixer coil are as follows: 

[Loss from any collecting circuit to the receiving"! = 10 Log 10 [n] Decibels 
|_ circuit or conversely J 

fLoss from one collecting circuit to another collect-"! _ 9 n T 

L ing circuit of the same pair J ^TrT 

fLoss from one collecting circuit to another collect-"! _ 9n T _,. r n 

. . P t . rv I ^w J-/U&10 III 

L mg circuit of different pairs J 

The mathematical means of deriving the above formulas will not 
be given in this paper. From a circuit standpoint such analysis is 
not difficult, but the actual manipulation of the circuit equations is 
somewhat tedious unless approached from the right point of view. 
In connection with the above losses it should be remembered that 
these are for theoretical transformers not dissipating power them- 
selves. In practice the transformer loss must be added to the above 
losses. The transformer loss for mixer transformers is of the same 
order as for any transformer of a comparable design. 

It is not the purpose of the paper to go into the detailed design of 
the transformer. However, it may be said that for "n" collecting 
circuits, ''n" associated windings are needed, arranged in pairs as 
shown in the schematics. If the inductance of each of the collecting 
windings is L henrys, then the inductance of the receiving winding 
is (nL) henrys. Also looking into the transformer from the receiving 
side with the other sides loaded with collecting circuits, the balancing 
resistors R B are not effective in determining the impedance. Hence 
the "n" collecting windings of L henrys each may be placed in series 
and attached to a load of (n R ) ohms. For this condition the trans- 
former is the same as any conventional transformer working from 
R ohms on one side to (n R ) ohms on the other side. This gives a 
convenient basis for carrying out the detailed design work. 

Thus the mixer transformer is a means of dividing one signal cir- 



Sept., 1944 RERECORDING CONSOLE, CIRCUITS, AND EQUALIZERS 197 

cuit into ^everal, or joining several into one on a matched impedance 
basis at all connecting points. The transmission loss is the minimum 
that can be obtained from any passive circuit arrangement effecting 
the. same result. When used with the console mixer circuit patching 
points are made available on a group basis at a number of places, thus 
greatly facilitating the use of the mixer networks. 

Constant B Equalizers. In the engineering of these new mixing 
facilities one of the worth-while features was the design of a new 
electrical circuit for the variable-type equalizers, resulting in im- 




FIG. 9. Conventional equalizer characteristics. 

proved equalization characteristics for the different control steps. 
These networks are termed "Constant B Equalizers" for reasons 
which will be evident later. The design methods employed are an 
extension of the theory presented in the book, Motion Picture Sound 
Engineering,- and where possible the same notation and concepts 
are used. It is believed that the constant B equalizer design is a 
new solution to the variable equalizer problem. 

Variable networks used in rerecording rooms are almost exclusively 
of the constant resistance type where present-day design technique 
permits. This provides flexibility of circuit patching. For wave 
filters this feature is not fully realizable for technical reasons, but for 



198 



W. C. MILLER AND H. R. KIMBALL 



Vol 43, No. 3 



equalizers constant resistance circuits are available in many forms. 
Variable characteristics are usually obtained in a step-by-step manner 
by means of control dials associated with tapped electrical elements. 

Continuously variable networks have not been used to any great 
extent as yet in motion picture work. Variable equalizers for rerecord- 
ing work usually require 2 degrees of freedom of control ; that is, the 
amount of equalization and its frequency placement must be in- 
dependently adjustable. An equalizer, for instance, arranged for 
equalization control with fixed frequency placement is not of much 
use to a mixer except for special purposes. 

One method which has been used extensively in the past for de- 
signing equalizers is to associate reactive circuit elements with re- 



VWNMr 

ZA 



Ro * 



VWWV \AMMr 
Ro Ro 



ZB 



*- Ro 



FIG. 10. Constant resistance equalizer section schematic. 

sistors forming attenuators of the various types. For variable net- 
works conventional step-by-step attenuators are often used instead 
of individual resistors. In order to vary the frequency placement 
of such networks it is necessary to employ tapped reactors whereby 
the actual values of the circuit reactances are changed by means of 
a control dial. To vary the amount of equalization it is customary 
to change the setting of the attenuator dial. This, however, is not a 
completely desirable procedure because the slopes of the family of 
equalization curves so obtained change from one attenuator setting 
to another. Fig. 9 shows a family of curves obtained in this manner 
where the change in slope may be noted. 

To acquire design control of the shape of these characteristics it is 
again necessary to simultaneously alter the reactance values. But 
where the tapped reactance method is used for frequency placement 



Sept., 1944 RERECORDING CONSOLE, CIRCUITS, AND EQUALIZERS 199 

it is obviously not practicable to repeat the process to control the 
amount of equalization. The use of the constant B attenuator 
provides an alternate method for controlling the slopes of the equal- 
ization curves without using tapped reactors, thus reserving this 
feature for frequency placement. 

Consider first the simple conventional constant resistance circuit 
of Fig. 10. For this circuit the resistors Ro are the same as the as- 
sociated line resistances. The impedors Z A and Z B are general in 
nature, composed of any circuit arrangement of resistors, and in- 
ductive or capacitive reactors, with the restriction that Z A and Z H 

CONSTANT B ATTENUATOR 




ZO ' 



*- Zo 



FIG. 11. Constant B equalizer schematic. 



are mutually inverse to each other, or Z A Z B = R 2 . Because of this 
relation, when one of them is known the other is determinable. 
Hence formulas associated with this network need to include only 
one or the other of the impedors. Inverse networks are discussed 
in the aforementioned book. 2 The insertion loss of the network of 
Fig. 10 is: s 



^ Decibels 



Insertion Loss in Db = 20 Logio 



The general circuit schematic for the constant B design is shown 
in Fig. 11. The circuit portion included within the dotted lines is 
the constant B attenuator. Resistors R are, as before, of the same 



200 W. C. MILLER AND H. R. KIMBALL yol 43, No. 3 

value as the line resistance. Resistors R Al , R A ,, R Bl , and R B . 2 
form the variable portion of the constant B attenuator. They cor- 
respond to the tapped resistors used in conventional attenuators. 
Constant B attenuators may be constructed physically in the same 
manner as conventional attenuators except that provision must be 
made to vary 4 resistors instead of the usual 2 or 3 resistors. The 
reactors JXi and JX 2 are general in their circuit arrangement but, as 
before, must be inverse to each other; (JXi) (JX 2 ) = Ro 2 . In associa- 
tion with the constant B attenuator they complete a constant B 
equalizer. 

The numerical impedance of any theoretically pure reactance or 
combination of reactances, as JXi and JX2 are assumed to be, varies, 
with frequency between a zero value at the resonant frequencies and 
an infinite value at the anti-resonant frequencies. For 2 mutually 
inverse reactances, one passes through zero reactance at the fre- 
quency for which the other exhibits infinite reactance, and conversely. 
Referring to Fig. 11 at the frequency for which JXi is zero and JX 2 
is infinite, the resistances R Al and R Az are in parallel and R Bl and 
RB Z are in series. Also, at the frequency for which JXi is infinite and 
JX 2 is zero neither of the resistances R Al nor R Bl is effective in the 
circuit. This, then, fixes the minimum and maximum losses over 
the frequency range. Using Eq (1) and letting R P be the parallel 
resistance of R Al and R Az we have 

Maximum Loss = 20 Logio fl + TT^ I Decibels (2} 

L M> J 

Minimum Loss = 20 Logio fl + ~~\ Decibels (3) 

Another loss called the equalization loss or simply equalization, is 
defined as the difference between the maximum and minimum losses, 
that is 

Equalization = Maximum Loss Minimum Loss 



Equalization = 20 Logio 



"11*1 
J + tf. 



Decibels (4} 



Note that equalization, as herein used, is a difference value not 
depending on frequency. For any particular design the equalization 
is varied by means of a control dial associated with the constant B 
attenuator. In most cases it is convenient to arrange the equaliza- 



Sept., 1944 RERECORDING CONSOLE, CIRCUITS, AND EQUALIZERS 201 

tion to vary in db, or multiple db steps from zero to some maximum 
amount obtained on the top step of the control ^dial. Equalization, 
then, and the manner in which it is to be varied, is assumed to be 
known design information. 

Another parameter useful in the design of equalizers is a frequency 
which we will call (f b ) and for which, on any control step, one-half the 
equalization loss for that step is obtained. That is, the equalizer loss 
varies from the minimum loss of Eq (3) to the maximum loss of Eq (2) 
and at one or more frequencies in between these 2 extremes, one-half 
the difference loss is obtained. Where fb is multivalued with fre- 
quency, use is made of the lower value in the formulas of the book, 
Motion Picture Sound Engineering? and this concept is retained here- 
in. f b , then, is known design information denned as follows: 

f b = Frequency of One-half Equalization Loss (5) 

Since equalization has been taken as the difference between the 
maximum and minimum losses as given in Eqs (2) and (3), it is 
obvious that a given amount of equalization can be obtained for an 
infinite number of values for these 2 losses as long as their difference 
is unchanged. But although this difference may remain constant, 
the equalization characteristics so obtained shift in the f b frequency. 
Then, for any definite amount of equalization, adjusting the maximum 
and minimum losses while keeping their difference constant provides' 
a means of placing f b at a desired frequency. Constant B equalizers 
hold f b at a constant frequency for all of the steps of the equalizer. 
The following equation supplies the design means for adjusting the 
maximum and minimum losses at the proper values for holding f b con- 
stant throughout the constant B attenuator range : 

(Max. loss ~| |~ Equalization ~| ("Max. Equalization! 

on any step = Sinh on same step X Sinn on top step (6) 

2 X 8.68 J L 2 X 8.68 J 2 X 8.68 

This is a coupling equation relating the 2 known losses contained 
in the right side of the equation to the unknown loss embodied in the 
left side of the equation. Eq (6) is derivable by rigorous mathe- 
matical processes not given here. Any equalizer having the circuit 
of Fig. 11, and having its attenuation losses related as in Eq (6) will 
maintain f b constant with frequency for all its attenuator steps and 
for any pair of associated inverse reactance circuits. 

An important simplication of Eq (6) can be made which avoids the 
use of hyperbolic functions in most cases. For equalizers having 



202 



W. C. MILLER AND H. R. KIMBALL 



Vol 43, No. 3 



maximum losses not greater than 15 or 20 db, the hyperbolic angles 
embodied in the equation are small angles. For small hyperbolic 




FIG. 12. Constant B equalizer characteristics. 



T 



P- 

ADD 



L2 



i JLC 

SUB 



i r 



CONSTANT B ATTENUATOR 



0000 



FIG. 13. "Add" and "Subtract" constant B equalizer schematic. 

angles, the sinh of the angle is approximately equal to the angle itself. 
Then we may write as a close approximation of Eq (6*) 

F Max. loss ~| 2 _ ("Equalization j ^ FlVIax. Equalization J /^ 

Lon any step J [_on same step J L on top step J 



Sept., 1944 RRRRCORDING CONSOLE, CIRCUITS, AND EQUALIZERS 203 



All the information needed to design the constant B attenuator 
portion of Fig. 11 is now before us. Knowing the items expressed 
in the right side of Kqs (6') or (7), 
the maximum loss as given by the 
left side of the equations for each 
equalization step may be com- 
puted. Then by means of Eqs 
(2) and (3) the values of the 
tapped resistors R Al and R A , for 
each equalization setting are ob- 
tainable. Since R Bl and R B2 are, 
respectively, inverse to R Al and 
R A , these resistors may now be 
computed for each equalization 
step. 

The reactances JXi and JX 2 
are designed to place the half 
loss frequency f b at the desired 
place in the frequency range. 
Because f b remains constant after 
being established, we may de- 
sign the reactances in connec- 
tion with any of the equalizer 
steps we desire. The most con- 
venient step is the top step where 
the equalization is a maximum 
and is also equal to the maxi- 
mum loss as seen from Eq (7). 
This means that the minimum 
loss is zero on the top step or 
R Al = 0. For this maximum loss 
condition then, the constant B 
equalizer circuit of Fig. 11 re- 
duces to the conventional types 
discussed in Motion Picture Sound 
Engineering. 2 The reactances 
JXi and JX 2 may therefore be 
designed for the maximum loss condition, in accordance with the 
information given therein and used with the constant B attenuator. 

Fig. 12 shows a constant B equalizer circuit and its character- 




FIG. 14. 



Front view of console equal- 
izer unit. 



204 



W. C. MILLER AND H. R. KIMBALL 



Vol 43, No. 3 



istics designed in accordance with the foregoing. The reactances 
employed with the constant B attenuator of this circuit are the same 

as those used in Fig. 9 in connec- 
tion with a conventional attenu- 
ator. The difference in the 
equalization characteristics for 
the 2 cases is noted. The maxi- 
mum equalization characteristic 
is the same in both cases. 

The equalizer of Fig. 12, when 
inserted in a circuit carrying a 
signal, effectively increases the 
relative volume of the frequency 
components in the vicinity of 
1000 cps. This equalizer can be 
made to decrease the relative 
level of these signal components 
by interchanging the series and 
shunt reactance circuits. Fig. 
13 shows a circuit for accomplish- 
ing this purpose where the switch- 
ing positions are designated as 
"Add" and "Subtract" corre- 
sponding to a relative increase or 
decrease of these frequency com- 
ponents. The families of equali- 
zation characteristics obtained 
for the add and subtract con- 
ditions are not necessarily sym- 
metrical, but can be made to be 
so by placing a limitation upon 
the maximum loss of the con- 
stant B attenuator. Reference 
to the design formulas given 
in Motion Picture Engineering' 2 ' 
for these 2 types of networks 
indicates that symmetrical add 
and subtract characteristics will be attained when the maximum 
loss of the constant B attenuator is 8.36 db. This is the loss cor- 
responding to the relation (K l)/\/K = l or K = 2.62 and loss = 
20 log 2.62 = 8.36 db. 




FIG. 15. 



Rear view of console equal- 
izer unit. 



Sept., 1944 RERECORDING CONSOLE, CIRCUITS, AND EQUALIZERS 205 

The design of the equalizer units used in the rerecording console 
shown in Figs. 14 and 15, is an application of the above information . 
vSix of these units are included in each rerecording console. Their 
constant B attenuators are designed to have the above-mentioned 
maximum loss of 8.30 db to make the add and subtract character- 
istics symmetrical. 

The reactors employed are tapped and associated with dials on 
the control panel to allow sweeping of the equalization character- 
istics throughout the frequency range. Because of the difficulty 
in securing tapped reactors having sufficient range, each equalizer 




FIG. 16. Typical "Add" and "Subtract" constant B equalizer characteristics. 

unit is really 2 units connected in series, one to cover the frequency 
spectrum below 1000 cps and the other effective above 1000 cps. 
This is indicated in the pre-set circuit schematic of Fig. 7. 

The frequency control dials consist of 20 steps, 10 for the lower 
unit, and 10 for the upper unit. These equalizer units, then, pro- 
vide 2 degrees of control freedom independent of each other, one to 
sweep the frequency range, and a second to vary the equalization. 
Fig. 16 shows samples of the equalization characteristics obtained. 

REFERENCES 

1 LAMBERT, K. B.: "An Improved Mixer Potentiometer," /. Soc. Mot. Pict. 
Eng., XXXVH (Sept., 1941), p. 283. 

2 Motion Picture Sound Engineering, D. Van Nostrand Co., Inc. (New York), 
1938. 



REPRODUCTION OF COLOR FILM SOUND RECORDS* 
R. GORISCH AND P. GORLICH 

The question of a sound record on color film seemed to have arrived 
at a final solution, because only a few of the proposed color film proc- 
esses satisfied the constantly increasing requirements, and therefore 
the possibilities for sound recording became less numerous. Silver 
sound tracks were recommended for the more successful color film 
processes, as for example, in the case of Agfacolor film, where by 
means of a special protecting method, a black-and-white instead of 
a colored track was obtained, or in the Technicolor process, where 
black-and-white stock already containing the sound record served as 
a base on which color transfers were made. However, this technical 
development was interrupted, when, for reasons of simplicity and 
perhaps of cost, it was tried in the Agfacolor process to produce a 
colored sound track exactly in the same manner as the picture. The 
following discussions deal with the phenomena occurring in the 
reproduction of such colored sound tracks. In conclusion and for 
the evaluation of the results new types of photoelectric cells will 
also be discussed. 

Even the first educational and advertising films prepared by the 
Agfacolor process showed that the correct reproduction of sound 
offered greater difficulties with a colored track than in the case of 
black-and-white. This phenomenon was not particularly studied 
at that time because this color process was only in the experimental 
stage. However, since regular features are' now produced by this 
process, it seems worth while to study the problem more closely. 
Even when the first experiments were made, it was found that the 
volume control of the reproducer had to be adjusted to a higher setting 
if a colored track was played, and that the noise level of such a track 
was much increased. High in the case of fresh prints, it rapidly be- 
came unbearable, as the film wore out. 

* Reprinted from Kinotechnik, 24 (Apr., 1942), pp. 43-46; translation by 
Werner Eichler, Research Laboratories, Eastman Kodak Company, Rochester, 
N. Y. 
206 



REPRODUCTION OF COLOR FILM SOUND RECORDS 



207 



For a study of the question of whether these two phenomena are 
connected, and what is their cause, we have made some experiments 
which will now be reported. First, however, we shall briefly men- 
tion previous publications on the question of the reproduction of 
colored sound tracks. 

The question of colored sound tracks has been discussed for a long 
time in connection with earlier 2-color films. These films used posi- 
tive stock coated on both sides with emulsion layers that were toned 
in complementary colors, and the question arose on which side the 
sound track should be printed. Otis 1 found that this question can- 
not be answered in a general way, but that it was important to know 
the spectral sensitivity of the photoelectric cell used for reproduc-. 




BOO 900 1000 myj 



CESIUM OXIDE CELL 
- CS- Sb CELL 



FIG. 1. Density of Agfacolor sound track as a 
function of wave length. 

tion. He found, for example, that, if the sound track of the multi- 
color film is in the blue layer, the film is much better reproduced with 
a red-sensitive caesium cell than with a blue-sensitive potassium cell. 
The reason for this is that the light modulation of the blue-toned 
sound track runs between blue and white, and that blue light does 
not appear appreciably darker to a blue-sensitive cell than white 
light. To a red-sensitive cell, however, the blue parts of the track 
appear almost opaque. 

Because of these considerations, it was proposed 2 that each of the 
several colored layers could contain a different sound record, perhaps 
in different languages or covering different frequency ranges, etc., 
and anyone could be selected for reproduction by changing the photo- 
electric cell, or by using colored filters in connection with a cell sensi- 
tive to all colors. As interesting as this proposition was, it failed 



208 



R. GORISCH AND P. G6RLICH 



Vol 43, No. 3 



because the absorption regions of the available dyes overlapped. 
Later it was tried to place identical tracks in all layers and thus elimi- 
nate the defects characteristic of a single-layer soundtrack. 3 This 
consideration led to the suggestion of the black-and-white silver 
sound track, as described in the beginning. 

The fact that a color-developed sound track cannot be avoided in 
certain processes suggested investigations of the expected noise level, 4 
and also of the sound volume and distortion. 6 The results of these 
investigations do not show that these simplified colored sound tracks 
are necessarily unsatisfactory. 



075 



0.5 



MAX. TRANSMISSION 



MIN. TRANSMISSION 




700 800 

CESIUM OXIDE CELL 
CS-Sb CELL 



1000 my 



FIG. 2. Transmission of Agfacolor sound track and fog as a 
function of wave length. 



The chemical structure of the sound track is immaterial, and the 
results are. mainly determined by its absorption characteristics in the 
spectral regions in which the reproducer photoelectric cell is sensitive. 
The investigation of the question, why the sound volume is low and 
the noise level high, must start at this place. Fig. 1 shows spectro- 
photometric curves of Agfacolor sound track made at areas of maxi- 
mum and minimum densities. 

The abscissa [Fig. 1 translator] shows the wave length of the 
light and the ordinate the corresponding density. The measurement 
was carried out in 2 steps, first for the visible light and the long-wave 
ultraviolet, and then for the infrared and the connecting red part of 
the spectrum. 

In order to show more clearly the phenomena in sound reproduc- 



Sept., 1944 REPRODUCTION OF COLOR FILM SOUND RECORDS 



209 



tic MI, Fig. 2 shows the same measurements converted from density 
to transmission. The distance between the 2 curves at any wave 
length represents the greatest possible sound modulation at that 
wave length for this type of track. Therefore, the region between 
the 2 curves is crosshatched in Fig. 2. If we start from the premise 
that the spectral sensitivity of the photoelectric cell must be adapted 
to the region of greatest possible modulation, we should use for this 
film a photoelectric cell which has a sensitivity only in the visible 
region, especially at about 650 mju. However, this is not the case in 
modern photoelectric cells. Their sensitivity maximum lies in the 




300 



FIG. 3. Relationship between photocell current and wave length 

. for Agfacolor sound track and 2 photocells of a different type. The 

spectral sensitivity curves of the 2 photocells as reduced to equal 

energy input and the spectral characteristic of the exciter lamp are 

also shown. 

infrared, therefore, in a region in which the maximum density of the 
sound record is low, their transmission, therefore, is very great. In 
addition, the sound lamp radiates more strongly in the infrared than 
in the visible spectrum. If we multiply for each wave length the 3 
factors influencing the magnitude at the photoelectric current, that is, 
film transmission, sensitivity of the cell, and sound lamp radiation, 
as is done in Fig. 3, we obtain the spectral distribution of the product 
for these cells as shown by the curves of Fig. 3 represented by the 
designation caesium oxide cell. The 2 cases of maximum and mini- 
mum density are shown. The area lying between such a curve and 
the abscissa corresponds to the total current flowing through the 
photoelectric cell. The area between the average of the 2 curves 
and the abscissa represents, therefore, the average photocell current, 



210 R. GORISCH AND P. GORLICH Vol 43, No. 3 

the area between the 2 curves the photocell modulation. For the 
caesium oxide cell we cannot expect good results on account of the 
poor relation between the 2 areas. 

If we substitute for the infrared-sensitive photoelectric cell, a cell 
which has its sensitivity maximum in the region of the blue light 
(Cs, Sb cell), entirely different curves are obtained. These curves 
are also recorded in Fig. 3, and the sound lamp radiation is considered 
as before. It is seen that for these cells a much more favorable 
relation exists between the photocell rest current and the modulation 
alternating current. 

In order to extend these results to the practice, a sound strip was 
photometered with the same cells. The following values were 
obtained: 

Caesium Oxide Cell Cs, Sb Cell 

Per Cent Per Cent 

T max . 88 60 

T min . 70 7 

A T 18 53 

T R 79 33.5 

These values clearly explain the low sound modulation with the 
use of the customary cells. Kuster 5 compared in his work the color 
reversal film with a silver reversal film. He found a lower modular 
tion for the color film which revealed scattered values even if photo- 
cells of one type were used so that, apparently, small differences in 
individual cells have a considerable effect. However, only caesium 
cells were studied. 

On the question of background noise it has been found previously 1 
that in the conversion of a silver image to a dye image a change of the 
background noise occurs. This may be calculated by determining 
the change in the transmission of the layer. However, this is merely 
noise from grain, or that part of the background noise which is based 
on the grain structure and which is heard only with entirely un- 
damaged film. This is less important in practice because the so- 
called scratch noise, including all the noises due to dust particles, 
scratches, dirt spots, etc., is normally stronger and increases con- 
siderably after the film has been used for some time. This scratch 
noise is proportional to the average transmission of the sound track, 
because all dust particles and other irregularities cause a much greater 
light impulse, if the film is more transparent. The last line of the 
table shows that for normal photocells the average transmission T R of 



Sept., 1944 REPRODUCTION OF COLOR FILM SOUND RECORDS 211 

the color sound track is very high and, consequently, when this cell is 
used a very strong background noise must be expected, which is even 
increased as the reproducer gain is raised on account of the low 
modulation. 

Therefore, the two phenomena of low sound modulation and high 
ground noise are connected with each other, and both have their 
cause in the improper adaptation of the photocell to the absorption 
of the dyes composing the sound record. It is clear that the use 
of other photocells will give much better results. The right column 
of the table contains the values for a blue-sensitive photocell. It is 
seen that the modulation is much greater than that of the caesium cell 
and that the average transmission is decreased. Practice has shown 
that color-developed sound records can be reproduced well with these 
cells. 

These explanations show why the external photoelectric effect was 
chosen for sound reproduction from the group of photoelectric phe- 
nomena. In addition to the advantage of the great internal resistance 
of these cells 6 they have the further advantage neglected for many 
years, that the spectral sensitivity of the cell can be changed accord- 
ing to the purpose and depending on the choice of the cathode material 
or the cathode layer. The caesium oxide cell generally fulfilled the 
requirements of sensitivity and spectral distribution for the re- 
production of silver sound tracks. We disregard here the frequent 
desire to shift the spectral distribution of these cells beyond 1200 m/x 
toward the infrared in order to be able to use the red rays of the 
sound lamps better. 

Research in the field of high-sensitive oxidized alkali cathodes, 
among which is the caesium oxide cathode, was promoted mostly 
by Asao, de Boer, Kluge, and Gorlich and, referred to the caesium 
oxide cathode, gave approximately the following picture: 7 The 
caesium oxide layer coated on a silver support contains caesium 
atoms. Adsorbed caesium atoms are on the surface and decrease 
the energy necessary to liberate electrons so that the degree of cover- 
age plays an important part. The photoelectric sensitivity may be 
increased by additional introduction of foreign metal atoms. 

The requirement of the photocell with respect to colored sound 
track, namely, a spectral distribution in the blue and violet part of 
the visible spectral region, is fulfilled not only by potassium oxide 
cells, which were studied mainly by Kluge, 8 but also by potassium 
hydride cells, studied bv Elster and Geitel. 9 With respect to the 



212 



R. G6RISCH AND P. GORLICH 



Vol 43, No. 3 



total photoelectric sensitivity, however, even potassium oxide cells 
are not satisfactory. 

It was, therefore, natural to adapt the caesium-antimony alloy 
cathode (Cs, Sb) 10 to meet the requirements of sound reproduction. 
This layer possesses high absolute sensitivity in addition to the 
desired spectral distribution (the long- wave maximum of sensitivity 
lies between 430 and 460 m/*). This is shown in Fig. 4. In this 
figure the product of V^S^ * s plotted against wave length X for the 
caesium oxide layer and also for the Cs, Sb layer. The integral 

Jph = cfV\S\d\ 



50 




500 600 700 

WAVELENGTH IN my 



800 



FIG. 4. Relative spectral response of caesium 
oxide and Cs-Sb photoelectric cells. 



gives the photoelectric current expected from the spectral distribu- 
tion F x and the energy distribution of the light source with known 
color temperature .Sx- Simultaneously, Fig. 4 gives the thermoelec- 
tric current which must be measured for the reduction of data to the 
same incident energy. 11 Practical workers will be interested to know 
that it has been possible to make gas-filled photoelectric cells with 
Cs, Sb layer in production which, when measured in the light of a 
normal sound lamp heated with 4.5 amp, have a sensitivity of 250 
M A/Lm, which is similar to that of gas-filled caesium oxide cells. 
This indicates that the Cs, Sb cell can be used for the reproduction of 
a colored sound track as well as for the silver track, and therefore, has 
a great advantage over caesium oxide cells. It is to be expected that 



Sept., 1944 REPRODUCTION OF COLOR FILM SOUND RECORDS 213 

further investigations will show the way to make cells with still 
higher sensitivities. 

The maximum of the spectral distribution may be shifted toward 
the red by about 100 m/x by sensitization with oxygen. Therefore, 
considerable specific adaptation to the spectral characteristics of any 
given film is possible. It will be of interest here to mention that 
even Schinzel's suggestion, 2 the use of a white-sensitive cell, can be 
carried out practically. By combination of a transparent Cs, Sb 
layer with a caesium oxide layer 12 in one cell, a photocell can be 
made which has a uniform sensitivity over the entire visible spectrum 
up to the near infrared. However, this cell may be expensive, be- 
cause its preparation requires the use of 2 different sensitization 
methods. 

In spite of a multitude of publications, 7 it is not yet clear in all de- 
tails what causes the great quantum efficiency of the Cs, Sb layers 
(maximum quantum efficiency of 30 per cent in comparison with 1 
per cent with caesium oxide cathodes). It seems that the electrons 
are liberated in a polyatomic layer of an alloy of Cs and Sb, whereby 
a fixed relation between both alloy components is necessary for the 
best results. In order to reduce the work function, a single-atomic 
Cs layer must be present on the surface of the alloy. 

REFERENCES 

1 OTIS, R. M.: "The Multicolor Process," /. Soc. Mot. Pict. Eng., XVII, 1 
(July, 1931), p. 5, in particular pp. 9-10; XVI, 2 (Feb., 1931), p. 151. 

2 SCHINZEL, K. : Kinotechnik, 11 (1929), p. 464; U. S. Pat. 1,675,894. 

3 D. R. PAT. 614,243 (Feb., 1932). 

4 GORISCH, R.: Beitrage zur Kenntnis des Grundgerausches von Tonfilmen, 
Diss. Univ. Berlin 1935, S. 20-21 ; appeared also in a series of sound film technical 
publications of the Klangfilm G.m.b.H., Berlin. 

5 KUSTER, A. : Kinotechnik, 21 (1939), p. 167, especially p. 169 et seq. 

6 Cf., e.g., GORLICH, P. '.Kinotechnik, 17 (1935), p. 307. 

7 GORLICH, P.: Zeitschr.f. Phys, 116 (1940), p. 704. 

8 KLUGE, W.: Phys. Zeitschr, 34 (1933), p. 115. 

9 ELSTER, J., AND GEITEL, H.: Phys. Zeitschr, 12 (1911), p. 609. 

10 GORLICH, P.: Zeitschr.f. Phys, 101 (1936), p. 335; Phil. Mag, 25 (1938), p. 
256; D. R. PAT. 713,401 (Aug., 1935); U. S. Pat. 2,122,860 (Aug., 1936), Brit. 
Pat. 460,012 (Jan., 1937). 

11 GORLICH, P.: J. Opt. Soc. Am., 31 (1941), p. 504. 

12 GORLICH, P.. AND LANG. W. : ZJ. Instrkde.. 57 (1937). p, 249. 



BOOK REVIEW 



A Guide to the Literature of Photography and Related Subjects. Compiled by 
Albert Boni, Quarterly Supplement No. 18 for the Photo-Lab-Index, by Henry M. 
Lester, Morgan & Lester, New York, 94 pp. 8 X 5 1 /* i n - 

A compilation of titles of books on photography and articles in photographic 
publications. 

Although the introduction to the book states "This guide makes no claim to 
being a complete index," the usefulness of any such compilation is greatly mini- 
mized if it is not reasonably complete. 

Among the general references to subjects such as cinematography, the outstand- 
ing foreign language journals, such as Kinotechnik and Journal of the British 
Kinemato graph Society, are omitted. 

Like many authors of photographic books and articles, the author of this work 
has failed to give adequate references to the many articles on practical and theo- 
retical photography contained in the Transactions and JOURNAL of the Society of 
Motion Picture Engineers. 

In many cases reference is made to the SMPE Index, while in other cases refer- 
ence is made to the particular SMPE article, but it would seem logical either to re- 
fer exclusively to the SMPE Index (for articles prior to December 1935), or to 
refer to the specific SMPE articles in all cases. A brief abstract is given of some of 
the references but this emphasis should not be taken as an index of the relative 
importance of the articles in question. 

It would seem advisable in future editions to omit the abstracts and utilize the 
space for more complete references. The following subjects would appear to be 
worthy of mention: Aeration of Developers, Agitation, Chrome Alum Fixing and 
Stop Baths, Fog, High Temperature Development, Rapid Processing, Replenish- 
ment of Developers, Resistivity of Construction Materials, Single Solution Dye 
Toning, Stains, Water Supply. 

J. I. CRABTREE 
July 17, 1944 



CURRENT LITERATURE OF INTEREST TO THE MOTION PICTURE 

ENGINEER 



The editors present for convenient reference a list of articles dealing with subjects 
cognate to motion picture engineering published in a number of selected journals. 
Photostatic or microfilm copies of articles in magazines that are available may be 
obtained from The Library of Congress^, Washington, D. C., or from the New York 
Public Library, New York, N. Y., at prevailing rates, 
214 



CURRENT LITERATURE 



215 



American Cinematographer 

25 (June, 1944), No. 6 
Cameras of the Past (p. 188) 
Television Picture Definition (p. 191) 
Monopack Processes (p. 192) 
Pola Screen and Filter Holders (p. 194) 

25 (July, 1944), No. 7 
Coated Lenses (p. 223) 
PH-346A Recording Equipment (p. 224) 
Experiments by an Army Cameraman (p. 229) 
Movie Tricks Explained (p. 231) 
A New 16-Mm Optical Printer (p. 232) 
New Mercury Vapor Lamp Announced (p. 238) 

Communications 

24 (June, 1944), No. 6 
Television Reception (p. 60) 

Educational Screen 

23 (May, 1944), No. 5 
Motion Pictures Not for Theatres, Pt. 56 (p. 207) 

23 (June, 1944), No. 6 
Motion Pictures Not for Theatres, Pt. 57 (p. 248) 

Electronic Engineering 

17 (June, 1944), No. 196 
Maintenance of Quality in Film-Recorded Sound, 

I Recording and Processing (p. 12) 
The "Kodatron" Speedlamp (p. 16) 
The Future of Electronic Music (p. 32) 

International Projectionist 

19 (May, 1944), No. 5 

Simplifying Analysis of Amplifier Circuits (p. 7) 
Television Today, Pt. VIII Radio Relays (p. 12) 
Coated Lenses and Their Efficiency (p. 20) 
Static Sparks from Rewind Machine Create Fire 
Hazard (p. 27) 

19 (June, 1944), No. 6 

Step-by-Step Analysis of Arc Rectifiers Sche- 
matics (p. 10) 
Television Today, Pt. IX Reproducers (p. 22) 



I. BROWNING 
L. H. BEDFORD 
J. S. FRIEDMAN 
F. DUPATY 

K. M. GREENLAND 
W. C. MILLER 
CAPT. T. E. HUNT 
P. TANNURA 
J. HARTLINE 



T. T. GOLDSMITH 

A. E. KROWS 
A. E. KROWS 



R. H. CRICKS 
G. A. JONES 
S. K. LEWER 



L. CHADBOURNE 

J. FRANK, JR. 

K. M. GREENLAND 

T. DRAHORAD 



L. CHADBOURNE 
J. FRANK, JR. 



FIFTY-SIXTH 
SEMI-ANNUAL TECHNICAL CONFERENCE 

OF THE 
SOCIETY OF MOTION PICTURE ENGINEERS 

HOTEL PENNSYLVANIA, NEW YORK, N. Y. 
OCTOBER 16-18, 1944 



Officers in Charge 

HERBERT GRIFFIN, President 

EMERY HUSE, Past-President 

LOREN L. RYDER, Executive V 'ice-President 

E. ALLAN WILLIFORD, Secretary 

W. C. KUNZMANN, Convention Vice-President 

D. E. HYNDMAN, Engineering Vice-P resident 

A. C. DOWNES, Editorial Vice-P resident 



Directory of Committee Chairmen 

Atlantic Coast Section C. R. KEITH, Chairman 

Papers Committee BARTON KREUZER, Chairman 

C. R. DAILY, Vice- Chair man, West Coast 

Publicity Committee JULIUS HABER, Chairman, assisted by 

MESSRS. DESFOR and BIDWELL 

Registration and Information W. C. KUNZMANN 

Reception and Local Arrangements. . E. I. SPONABLE 
Fifty-Sixth Semi-Annual Dinner- 
Dance D. E. HYNDMAN 

Membership and Subscription 

Committee JAMES FRANK, JR., Chairman 

Hotel and Transportation O. F. NEU 

Ladies Reception Hostess MRS. E. I. SPONABLE 

Projection 35-mm H. F. HEIDEGGER, Chairman, assisted by 

Members New York Projectionists Local 
No. 306 
16-mm. . . .M. W. PALMER 



SEMI-ANNUAL TECHNICAL CONFERENCE 217 

HOTEL RATES 

The Hotel Pennsylvania management extends to SMPE members and guests 
the following per diem rates, European plan: 

Room with hath, one person $3 . 85~$7 . 70 

Room with bath, two persons, double bed 5. .50- 8.80 

Room with bath, two persons, twin beds. 6.60- 9.90 

Parlor suites: living room, bedroom, and bath. .$10.00, $11.00, $13.00 and $18.00 

RESERVATIONS 

The Hotel Pennsylvania room reservation cards will be mailed to the member- 
ship of the Society early in September. If attending the Fall Conference, return 
your card with checked accommodations immediately to the hotel so your reserva- 
tion, which is subject to cancellation prior to October 15, can be booked and 
confirmed. No accommodations will be guaranteed unless confirmed by the hotel 
management. 

REGISTRATION 

The Fall Conference registration headquarters will be located on the 18th floor 
of the hotel adjacent to the Salle Moderne where all technical and business 
sessions will be held. Members and guests are expected to register, the fee for 
which is used to defray Conference expenses. 

TECHNICAL SESSIONS 

If you wish to participate in the Conference through presentation of a technical 
paper, it is essential that the title of the paper, name of author and abstract be 
mailed immediately to the Chairman or Vice-Chairman of the Papers Committee. 
Complete manuscripts must be received not later than October 1 for listing in the 
final program. 

FIFTY-SIXTH SEMI-ANNUAL DINNER-DANCE 

The Fifty-Sixth Semi-Annual Informal Dinner-Dance, award presentations, 
and social get-together, will be held in the Georgian Room of the hotel on Tuesday 
evening, October 17 (dress optional). Because of labor and rationing problems, 
the Dinner- Dance Committee must know in advance the number of persons 
attending this function. Therefore, it is essential to procure tickets from or 
make reservations through D. E. Hyndman, Chairman of the Dinner-Dance 
Committee, or through the General Office of the Society, Hotel Pennsylvania, 
on and after September 18. Tickets are $7.50 per person, taxes included. Check 
or money order should accompany requests for tickets and should be made 
payable to W. C. Kunzmann, Convention Vice-President. Only by receiving 
wholehearted cooperation can the Committee provide adequately for your 
evening's entertainment. 

LADIES' RECEPTION HEADQUARTERS 

Although there will be no prearranged ladies' entertainment program during 
the Fall Conference, a reception parlor will be available in the hotel for the 
ladies' daily get-together and open house with Mrs. E. I. Sponable serving as 



218 



SEMI- ANNUAL TECHNICAL CONFERENCE 



reception hostess. The ladies are invited to attend the Conference social func- 
tions. Ladies attending the Conference should register to receive badges and 
identification cards. 

MOTION PICTURES 

Conference identification cards issued to registered members and guests will 
be honored through the courtesy of the following de luxe motion picture theaters 
in New York : 

CAPITOL THEATRE 

PARAMOUNT THEATRE 

RADIO CITY Music HALL 

ROXY THEATRE 
WARNER'S HOLLYWOOD AND STRAND THEATRES 

There are many entertainment attractions available in New York to out-of- 
town members and guests, and information concerning these may be obtained at 
the hotel information desk or at the SMPE registration headquarters. 



Monday, October 16, 1944 

9: 00a.m. Hotel, 18th Floor: Registration. 
10: 00 a.m. Salle Moderne: Morning Session. 
12: 30 p.m. Luncheon period. 

2: 00 p.m. Salle Moderne: Afternoon Session. 

8:00 p.m. The program for the evening of this date will be announced later. 

Tuesday, October 17, 1944 

9: 00a.m. Hotel, 18th Floor: Registration. 
10:00 a.m. Salle Moderne: Morning Session. 
12: 30 p.m. Luncheon period. 

2: 00 p.m. Salle Moderne: Afternoon Session. 

8 : 00 p.m. Georgian Room: Dinner-Dance and social get-together. The evening's 
program will be announced later. 

Wednesday, October 18, 1944 

9: 30a.m. Hotel, 18th Floor: Registration. 
10: 00 a.m. Salle Moderne: Morning Session. 
12: 30 p.m. Luncheon period. 

2: 00 p.m. Salle Moderne: Afternoon Session and Adjournment. 

IMPORTANT 

When you receive your hotel room reservation card, please return it 
immediately if attending the Fall Conference. No rooms will be avail- 
able or guaranteed unless booked in advance of the Conference dates. 
Also, procure tickets for the Dinner-Dance before October 14 to insure 
accommodations. 

. W. C. KUNZMANN 

Convention Vice- President 



SOCIETY ANNOUNCEMENTS 



AMENDMENTS OF BY-LAWS 

At a meeting of the Board of Governors held in New York on April 16, 1944, 
it was unanimously voted to submit the following proposed amendments of 
By-Laws I and III to the membership of the Society for voting at the Fifty-Sixth 
Semi- Annual Technical Conference in New York, October 16-18, inclusive: 

Proposed Amendment of By-Law I, Sec. 3 (c) and (d) 

t "Sec. 3 (c) Applicants for Active membership shall give as references at least 
one member of Active or of higher grade in good standing. Applicants shall 
be elected to membership by the unanimous approval of the entire membership 
of the appropriate Admissions Committee. In the event of a single dissenting 
vote or failure of any member of the Admissions Committee to vote, this 
application shall be referred to the Board of Governors, in which case approval 
of at least three-fourths of the Board of Governors shall be required. 
"Sec. 3 (d) Applicants for Associate membership shall give as references one 
member of the Society in good standing, or two persons not members of the 
Society who are associated with the industry. Applicants shall be elected to 
membership by approval of a majority of the appropriate Admissions Com- 
mittee." 

Proposed Amendment of By-Law III, Sec. 4 

"The Board of Governors, when making nominations to fill vacancies in offices 
or on the Board, shall endeavor to nominate persons who in the aggregate are 
representative of the various branches or organizations of the motion picture 
industry to the end that there shall be no substantial predominance upon the 
Board, as the result of its own action, of representatives of any one or more 
branches or organizations of the industry." 

At a meeting of the Board of Governors held July 18, 1944, it was resolved to 
submit proposed amendments of By-Laws V and VI to the membership of the 
Society for voting at the Technical Conference in October, as follows: 

Proposed Amendment to By-Law V, Sec. 3 

"A quorum of the Society shall consist in number of one-fifteenth of the total 
number of Honorary members, Fellows and Active members as listed in the 
Society's records at the close of the last fiscal year." 

Proposed Amendment to By -Law VI, Sec. 3 (a) 

"The Executive Vice-President shall represent the President in such geographi- 
cal areas of the United States as shall be determined by the Board of Governors, 

219 



220 SOCIETY ANNOUNCEMENTS 

and shall be responsible for the supervision of the general affairs of the Society 
in such areas, as directed by the President of the Society. Should the President 
or Executive Vice- President remove his residence from the geographical area 
(Atlantic Coast or Pacific Coast) of the United States in which he resided at 
the time of his election, the office of Executive Vice-President shall imme- 
diately become vacant and a new Executive Vice-President elected by the 
Board of Governors for the unexpired portion of the term, the new Executive 
Vice-President to be a resident of that part of the United States from which 
the President or Executive Vice-President has just moved." 



COMMITTEES OF THE SOCIETY 

(Correct to August 15) 



The Board of Governors voted recently to publish in the JOURNAL regularly the 
personneland scope of all standing committees of the Society. It is believed 
these data will be of value not only to committee chairmen and members in having 
an up-to-date list of committee membership, but will be of interest to others who 
may be unfamiliar with the general nature of activities engaged in by the various 
technical and nontechnical committees of the Society. 



ADMISSIONS. To pass upon all applications for membership, applications for transfer and 
to review the Student and Associate membership list periodically for possible transfers to the 
Associate and Active grades respectively. The duties of each committee are limited to applica- 
tions and transfers originating in the geographic area covered. 

(East Coast) 

A. S. DICKINSON, Chairman 

M. R. BOYER JAMES FRANK, JR. D. E. HYNDMAN 

H. D. BRADBURY GEORGE FRIEDL, JR. HARRY RUBIN 

(West Coast) 

EMERY HUSE, Chairman 

C. W. HANDLEY W. A. MUELLER 

H. W. MOYSE H. W. REMERSHIED 

BOARD OF EDITORS. To pass upon the suitability of all material submitted for publica 
tior, or for presentation at conventions, and publish the JOURNAL. 

A. C. DOWNES, Chairman 

J. I. CRABTREE A. M. GUNDELFINGER C. R. KEITH 

A. N. GOLDSMITH C. W. HANDLEY E. W. KELLOGG 

A. C. HARDY 

CINEMATOGRAPHY. To survey the field of motion picture photography in an en- 
deavor to bring before the Society any information on current or future practice, and also to 
continually review this field for possibilities of standardization of any specific procedure. 

J. W. BOYLE, Chairman 

C. G. CLARKE *ARTHUR MILLER ARTHUR REEVES 

KARL FREUND JOSEPH RUTTENBERG 

COLOR. To survey the field of color in motion picture photography in an endeavor to bring 
before the Society any information on current or future practice, and also to continually review 
this field for possibilities of standardization of any specific procedure. 

R. M. EVANS, Chairman 

F. T. BOWDITCH A. M. GUNDELFINGER 

L. E. CLARK A. C. HARDY 



Advisory Member. 

221 



222 COMMITTEES OF THE SOCIETY Vol 43, No. 3 

CONVENTION. To assist the Convention Vice-President in the responsibilities pertaining 
to arrangements and details of the Society's technical conventions. 

W. C. KUNZMANN, Chairman 

J. G. FRAYNE SYLVAN HARRIS O. F. NBU 

*JULIUS HABER H. F. HEIDEGGER R. O. STROCK 

EXCHANGE PRACTICE. To survey the field of exchange practice in an endeavor to bring 
before the Society any information on current or future practice, and also to continually review 
this field for possibilities of standardization of any specific procedure. 

A. S. DICKINSON G. K. HADDOW N. F. OAKLEY 

*T. FAULKNER SYLVAN HARRIS A. W. SCHWALBERG 

G. R. GIROUX L. B. ISAAC J. SICHELMAN 

H. C. KAUFMAN 

FELLOW MEMBERSHIP. To consider qualifications of Active members as candidates for 
elevation to Fellow members, and to submit such nominations to the Board of Governors. 

EMERY HUSE, Chairman 

M. R. BOYER A. N. GOLDSMITH W. C. KUNZMANN 

A. S. DICKINSON HERBERT GRIFFIN L. L. RYDER 

A. C. DOWNES C. W. HANDLEY E. A. WILLIFORD 

D. E. HYNDMAN 

HISTORICAL AND MUSEUM. To collect facts and assemble data relating to the historical 
development of the motion picture industry, to encourage pioneers to place their work on record 
in the form of papers for publication in the JOURNAL, and to place in suitable depositories equip- 
ment pertaining to the industry. 

J. E. ABBOTT, Chairman 
O. B. DEPUE RICHARD GRIFFITH TERRY RAMSAYE 

HONORARY MEMBERSHIP. To diligently search for candidates who through their 
basic inventions or outstanding accomplishments have contributed to the advancement of the 
motion picture industry and are thus worthy of becoming Honorary members of the Society. 

E. A. WILLIFORD, Chairman 

J. I. CRABTREE EMERY HUSE 

A. N. GOLDSMITH L. L. RYDER 

JOURNAL AWARD. To recommend to the Board of Governors the author or authors of 
the most outstanding paper originally published in the JOURNAL during the preceding calendar 
year to receive the Society's Journal Award. 

SYLVAN HARRIS, Chairman 

F. G. ALBIN C. R. KEITH 

J. G. FRAYNE J. A. MAURER 

LABORATORY PRACTICE. To survey the field of motion picture laboratory practice in 
an endeavor to bring before the Society any information on current or future practice, and also 
to continually review this field for possibilities of standardization of any specific procedure. 

H. E. WHITE, Chairman 

A. C. BLANEY G. H. GIBSON J. M. NICKOLAUS 

L. A. BONN EMERY HUSE N. F. OAKLEY 

A. W. COOK T. M. INGMAN W. H. OFFENHAUSER, JR. 

O. B. DEPUE C. L. LOOTENS V. C. SHANER 

R. O. DREW *A. J. MILLER J. H. SPRAY 

J. A. DUBRAY H. W. MOYSE J. F. VAN LEUVEN 

J. G. FRAYNE J. R. WILKINSON 



* Advisory Member. 



Sept., 1944 COMMITTEES OF THE SOCIETY 223 

MEMBERSHIP AND SUBSCRIPTION. To solicit new members, obtain nonmember sub- 
scriptions for the JOURNAL, and to arouse general interest in the activities of the Society and its 
publications. 

[AMES FRANK, JR., Chairman 

T. C. BARROWS E. R. GEIB W. A. MUELLER 

J. G. BRADLEY L. T. GOLDSMITH H. B. SANTEE 

KARL BRENKERT SYLVAN HARRIS G. E. SAWYER 

G. A. CHAMBERS L. B. ISAAC W. L. THAYER 

L. W. CHASE W. C. KUNZMANN *C. R. WOOD 

J. P. CORCORAN S. A. LUKES E. O. WILSCHKE 

J. G. FRAYNE G. E. MATTHEWS W. V. WOLFE 

G. C. MlSENER 



NONTHEATRICAL EQUIPMENT. To survey the field of nontheatrical motion picture 
equipment in an endeavor to bring before the Society any information on current or future prac- 
tice, and also to continually review this field for possibilities of standardization of any specific 
procedure. 

J. A. MAURER, Chairman 

*F. L. BRETHAUER R. C. HOLSLAG *T. J. RESS 

F. E. CARLSON R. KINGSLAKE L. T. SACHTLEBEN 

JOHN CHRISTIE D. F. LYMAN A. SHAPIRO 

R. O. DREW W. H. OFFENHAUSER, JR. D. G. SMITH 

F. M. HALL M. W. PALMER M. G. TOWNSLEY 

J. A. HAMMOND A. G. ZIMMERMAN 



PAPERS. To solicit papers, and provide the program for semi-annual conventions, and make 
available to local sections for their meetings papers presented at national conventions. 

BARTON KREUZER, Chairman 
C. R. DAILY, Vice-Chairman 

F. T. BOWDITCH JAMES FRANK, JR. H. W. MOYSE 

G. A. CHAMBERS T. G. FRAYNE V. C. SHANER 
F. L. EICH C. R. KEITH S. P. SOLOW 
R. E. FARNHAM E. W. KELLOGG D. R. WHITE 
J. L. FORREST G. E. MATTHEWS W. V. WOLFE 

P. A. McGuiRE 



PRESERVATION OF FILM. To survey the field for methods of storing and preserving mo- 
tion picture film in an endeavor to bring before the Society any information on current or future 
practice, and also to continually review this field for possibilities of standardization of any specific 
procedure. 

J. G. BRADLEY, Chairman 

J. E. ABBOTT J. L. FORREST *W. F. KELLEY 

J. I. CRABTREE C. L. GREGORY TERRY RAMSAYE 

A. S. DICKINSON V. B. SEASE 



PROCESS PHOTOGRAPHY. To survey the field of process photography in an endeavor 
to bring before the Society any information on current or future practice, and also to continually 
review this field for possibilities of standardization of any specific procedure. 



WILLIAM THOMAS, Chairman 

F. R. ABBOTT *F. M. FALGE GROVER LAUBE 

A. H. BOLT C. W. HANDLEY G. H. WORRALL 

W. C. HOCH 



Advisory Member. 



224 COMMITTEES OF THE SOCIETY Voi 43, No. 3 

PROGRESS. To prepare an annual report on progress in the motion picture industry. 

G. A. CHAMBERS, Chairman 

F. T. BOWDITCH J. A. DUBRAY G. E. MATTHEWS 

G. L. DIMMICK M. vS. LESHING D. R. WHITE 

PROGRESS MEDAL AWARD. To recommend to the Board of Governors a candidate who 
by his inventions, research or development has contributed in a significant manner to the 
advancement of motion picture technology, and is deemed worthy of receiving the Progress 
Medal Award of the Society. 

J. I. CRABTREE, Chairman 
O. B. DEPUE J. A. MAURER 

G. E. MATTHEWS L. L. RYDER 

PUBLICITY. To assist the Convention Vice- President in the release of publicity material 
concerning the Society's semi-annual technical conventions. 

*JULIUS HABER, Chairman 
G. A. CHAMBERS *HAROLD DESFOR G. R. GIROUX 

C. R. DAILY P. A. McGuiRE 

SOUND. To survey the field of motion picture sound recording and reproducing in an en- 
deavor to bring before the Society any information on current or future practice, and also to con- 
tinually review this field for possibilities of standardization of any specific procedure. 

W. V. WOLFE, Chairman 

C. R. KEITH, Vice- Chair man 

M. C. BATSEL E. H. HANSEN W. A. MUELLER 

D. J. BLOOMBERG L. B. ISAAC HARRY RUBIN 

B. B. BROWN J. P. LIVADARY G. E. SAWYER 
F. E. CAHILL, JR. G. T. LORANCE S. P. SOLOW 

C. R. DAILY J. A. MAURER F. R. WILSON 
L. T. GOLDSMITH W. C. MILLER *E. C. ZRENNER 

K. F. MORGAN 

STANDARDS. To survey the various fields or branches of the motion picture industry in an 
endeavor to bring before the Society any information on current or future practice or methods 
that would lead to possibilities of standardization of any specific procedure. 

F. T. BOWDITCH, Chairman 

J. M. ANDREAS A. F. EDOUART G. A. MITCHELL 

P. H. ARNOLD J. L. FORREST W. H. OFFENHAUSER, JR. 

HERBERT BARNETT A. N. GOLDSMITH G. F. RACKETT 

M. C. BATSEL L. T. GOLDSMITH W. B. RAYTON 

M. R. BOYER HERBERT GRIFFIN HARRY RUBIN 

F. E. CARLSON A. C. HARDY L. T. SACHTLEBEN 

*T. H. CARPENTER D. B. JOY OTTO SANDVIK 

E. K. CARVER C. R. KEITH LLOYD THOMPSON 

H. B. CUTHBERTSON P. J. L/ARSEN J. F. VAN L/EUVEN 

L. W. DAVEE R. G. LINDERMAN H. E. WHITE 

J. A. DUBRAY C. L. LOOTENS A. G. ZIMMERMAN 

J. A. MAURER 

STUDIO LIGHTING. To survey the field of motion picture studio lighting in an endeavor 

practice, and 
c procedure. 






to bring before the Society any information on current or future practice, and also to continually 
review this field for possibilities of standardization of any specific 



C. W HANDLEY, Chairman 

J. W. BOYLE R. E. FARNHAM KARL FREUND 

H. J. CHANON W. W. LOZIER 



* Advisory Member. 



Sept., i44 COMMITTEES OF THE SOCIETY 225 

TECHNICAL NEWS. To survey the fields of production, distribution, and exhibition of 
motion pictures, and allied industries, to obtain technical news items for publication in the 
JOURNAL. 

A. C. BLANKY, Chairman 

M. R. BOYER A. M. GUNDELFINGER K. F. MORGAN 

J. W. BOYLE C. W. HANDLEY H. W. REMERSHIED 

J. I. CRABTREE EMERY HUSK WILLIAM THOMAS 

H. R. LUBCKE 

TELEVISION. Technical consideration of the uses of motion picture television service; 
technical consideration of the phases of television which effect origination, transmission, dis 
tribution, and reproduction of theater television. 

P. C. GOLDMARK, Chairman 

R. B. AUSTRIAN C. F. HORSTMAN PIKRRK MERTZ 

R. L. CAMPBELL L. B. ISAAC '*PAUL RAIBOURN 

E. D. COOK A. G. JENSEN P. H. REEDY 
C. E. DEAN . P. J. LARSEN OTTO SANDVIK 
A. N. GOLDSMITH H. R. LUBCKE R. E. SHELBY 
T. T. GOLDSMITH *I. G. MALOFF E. I. SPONABLE 
HERBERT GRIFFIN J. A. MAURER H. E. WHITE 

TEST FILM QUALITY. To supervise the quality of prints of test films prepared by the 
Society. 

F. R. WILSON C. F. HORSTMAN 

THEATER ENGINEERING. The Committee on Theater Engineering comprises the 
membership of the four subcommittees listed below and is under the general chairmanship of 
DR. ALFRED N. GOLDSMITH. 

Subcommittee on Film Projection Practice. To make recommendations and prepare specifi- 
cations for the operation, maintenance, and servicing of motion picture projection equipment, 
projection rooms, film storage facilities, and stage arrangements as they effect screen dimen 
sions, placement, and the maintenance of loudspeakers. 

L. B. ISAAC, Chairman 
M. D. O'BRIEN, Secretary 

HENRY ANDERSON J. K. ELDERKIN *J. H. LITTENBERG 

I 1 . C. BARROWS JAMES FRANK, JR. E. R. MORIN 

H. D. BEHR R. R. FRENCH J. R. PRATER 

M. F. BENNETT E. R. GEIB HARRY RUBIN 

KARL BRENKERT ADOLPH GOODMAN J. J. SEFING 

F. E. CAHILL, JR. HERBERT GRIFFIN R. O. WALKER 
C. C. DASH SYLVAN HARRIS V. A. WELMAN 
L. W. DAVEE J. J. HOPKINS H. E. WHITE 
A. S. DICKINSON C. F. HORSTMAN A. T. WILLIAMS 

I. JACOBSEN 

Subcommittee on Television Projection Practice. To make recommendations and prepare 
specifications for the construction, installation, maintenance, and servicing of equipment for 
projecting television pictures in the theater, as well as the projection room arrangements neces- 
sary for such equipment, and such picture-dimensional and screen-characteristic matters as 
may be involved in theater television presentation. 

L. B. ISAAC, Chair mun 
M. D. O'BRIEN, Secretary 

(Under organization) 



* Advisory Member. 



226 



COMMITTEES OF THE SOCIETY 



Subcommittee on Screen Brightness. To make recommendations, prepare specifications 
and test methods for determining and standardizing the brightness of the motion picture screen 
image at various parts of the screen, and for specific means or devices in the projection room 



adapted to the control or improvement of screen brightness. 



HERBERT BARNETT 
E. R. GEIB 
SYLVAN HARRIS 



F. E. CARLSON, Chairman 
W. F. LITTLE 
W. B. RAYTON 



C. M. TUTTLE 
H. E. WHITE 
A. T. WILLIAMS 



Subcommittee on Theater Engineering, Construction, and Operation. To deal with the 
technical methods and equipment of motion picture theaters in relation to their contribution for 
the physical comfort and safety of patrons so far as can be enhanced by correct theater design, 
construction, and operation of equipment. 

(Under organization) 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 


Vol43 OCTOBER, 1944 No. 4 

CONTENTS 

PAGE 

The Physical Properties and Dimensional Behavior of 
Motion Picture Film J. M. CALHOUN 227 



Aids for Pictorially Analyzing High-Speed Action 

E. M. WATSON 2&7 



Fast Motion Analysis as an Aid to Organized Invention 

E. M. WATSON 289 



Technical News 303 



Committees of the Society 305 



(The Society is not responsible jor statements oj authors.) 

Contents of previous issues of the JOURNAL are indexed in the 
Industrial Arts Index available in public libraries. 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

HARRY SMITH, JR., EDITOR 

ARTHUR C. DOWNES, Chairman 

Board of Editors 

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KELLOGG 
CLYDE R. KEITH ALAN M. GUNDELFINGER CHARLES W. HANDLEY 

ARTHUR C. HARDY 
Officers of the Society 
^President: HERBERT GRIFFIN, 

133 E. Santa Anita Ave., Burbank, Calif. 
* 'Past-President: EMERY HUSE, 

6706 Santa Monica Blvd., Hollywood, Calif. 
^Executive Vice-President: LOREN L. RYDER, 

6451 Marathon St., Hollywood, Calif. 
**Engineering Vice-President: DONALD E. HYNDMAN, 

360 Madison Ave., New York, N. Y. 
*Editorial Vice-President: ARTHUR C. DOWNES, 

Box 6087, Cleveland, Ohio. 
** Financial Vice-President: ARTHUR S. DICKINSON, 

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*Term expires December 31, 1944. 
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Subscription to nonmembers, $8.00 per annum; to members, $5.00 per annum, included 
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Engineers, Fnc., Hotel Pennsylvania, New York 1, N. Y. 

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers, Inc. 

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Picture Engineers. Inc. 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

Vol 43 OCTOBER, 1944 No. 4 



THE PHYSICAL PROPERTIES AND DIMENSIONAL 
BEHAVIOR OF MOTION PICTURE FILM* 



J. M. CALHOUN** 

Summary. A general discussion is given of the physical properties of both 
nitrate and safety motion picture film and how these properties are influenced by heat, 
moisture and other factors. Some of the improvements made in safety base in recent 
years are described together with some of its present weaknesses. 

The manufacture of film base is mentioned briefly and the influence of structure on 
physical properties is pointed out. The effects of moisture on film are discussed in- 
cluding the relation between equilibrium moisture content and relative humidity, the 
rate of swell in water, the rate of drying, and the rate of conditioning. The physical 
changes which occur in the processing and drying of film by continuous machine are 
described. 

The mechanical properties of film, such as tensile strength, elongation, modulus of 
elasticity, cold flow, folding endurance, and tearing resistance, are discussed and com- 
parisons made between various films. The effect of relative humidity and temperature 
on the brittleness of film is described, with particular rejerence to low relative humidi- 
ties and subzero temperatures. Tackiness is mentioned briefly. 

Temporary and permanent film shrinkage of various types is explained, and the 
factors which affect shrinkage throughout the life of the film are discussed. The shrink- 
age characteristics of a number of Eastman motion picture films are tabulated. The 
cause of curl is explained, as well as the changes in curl, which occur during processing 
and storage. Recommendations are made throughout on the handling and storage 
of film to obtain the best performance. 

The proper performance of motion picture cameras, printers, proc- 
essing machines, and projectors and, therefore, the screen quality, 
depends to a very large degree on the physical properties of the 
photographic film. The useful life of the film itself is determined to 
a considerable extent by its physical characteristics. A large in- 
crease in the use of safety film for Army and Navy training purposes 
during the war has led to many new problems, due in part to the 
differences between nitrate and safety base and in part to the severe 

* Presented Feb. 23, 1944, at a meeting of the Atlantic Coast Section of the 
Society in New York. 

** Eastman Kodak Company, Rochester, New York. 

227 



228 



J. M. CALHOUN 



Vol 43, No. 4 



use to which such training films are put. The purpose of this paper 
is to describe a few of the fundamental physical characteristics of 
motion picture films which, it is hoped, will give a clearer under- 
standing of both nitrate and safety materials. A discussion of how 
the physical properties of the film affect several specific practical 
problems is given by R. H. Talbot. 1 

THE MANUFACTURE OF PHOTOGRAPHIC FILM 

Present-day motion picture films consist essentially of a light- 
sensitive gelatin layer coated on a flexible cellulose nitrate or ace- 
tate base.* In common with various other plastic materials, photo- 




01 2345 

TIME - HOURS 

FIG. 1. The rate of curing of a green cellulose 
acetate film base at 200 F. 

graphic films display many physical characteristics which differ 
considerably from those of flexible metal films. Therefore, a brief 
description of the manufacture of photographic film base at this 
point should assist in the discussion to follow. 

In the manufacture of both nitrate and safety film base, a viscous 
honey-like solution or dope of the cellulose derivative in suitable 
organic solvents, generally containing plasticizers, is first cast upon 
a smooth metal wheel or roll. Enough solvent evaporates as the 
wheel revolves so that before one complete revolution, the film skin 



* Safety film base made by the Eastman Kodak Company may be either cellu- 
lose acetate or a mixed cellulose ester such as cellulose acetate propionate or 
cellulose acetate butyrate. Throughout this paper "cellulose acetate" is used as a 
general term to include these mixed esters as well as cellulose acetate itself. 



Oct., 1944 PROPERTIES AND BEHAVIOR OF FILM 229 

has sufficient strength to be stripped from the metal surface. It is 
then passed through a complex series of heated chambers to drive 
out the remaining solvent. 

Unfortunately, in practice it is not possible to remove every trace 
of solvent from the film base. Fig. 1 illustrates the shape of a 
typical curing curve for green film base and shows that the rate of 
solvent removal decreases rapidly as .curing proceeds. The last 
traces of solvent are held very tenaciously by the base. In commer- 
cial production it is obviously impossible to increase the curing time 
beyond a certain limit. Therefore, in spite of the improvements 
made in recent years, there is always some residual solvent in the 
film base which, with small amounts of plasticizer, gradually diffuses 
out of the film throughout its life, resulting in a certain amount of 
shrinkage and related troubles. 

A word concerning the structure of film base may be helpful at 
this point. Cellulose nitrate and acetate molecules are generally 
considered to be long chains which may or may not be grouped to- 
gether in clusters or bundles called micelles. 2 The exact dimensions 
of the molecules or micelles probably vary even within the same 
sample, but it is their approximate shape which is of interest here. 
McNally and Sheppard, 3 following a study of the optical properties 
of cellulose nitrate and acetate films, concluded that whatever the 
nature of the particles involved " it appears that they must be un- 
symmetrical in shape, rod- or lath-like, having one axis considerably 
longer than the others.'' All of the available evidence obtained from 
studies of the physical properties and dimensional behavior of film 
base confirms this view. 

Since the film base is pulled rather than pushed through the curing 
chambers, it is unavoidably stretched and strained to some extent 
in the machine direction (lengthwise). If the base is sufficiently 
warm and soft when stretched, the molecules (or micelles) tend to 
become partially oriented in the direction of stretch. This pro- 
duces a slight "grain" in the film base which affects the strength, 
tear resistance, shrinkage, and other physical properties of the 
film which will be described later. If the base is not sufficiently 
warm and soft when stretched, the deformation produces a me- 
chanical strain in the film. 4 When the base is cooled rapidly, the 
deformation remains a phenomenon referred to as the "freezing-in 
of strain." 5 This deformation or strain may be released sometime 
during the life of the film with a consequent lengthwise shrinkage. 



230 



J. M. CALHOUN 



Vol 43, No. 4 



MOISTURE RELATIONSHIPS IN PHOTOGRAPHIC FILMS 

One of the most important physical characteristics of a photo- 
graphic film is its susceptibility to moisture. A film which is too 
moist is weaker, is more easily stretched and distorted, and may be 
tacky. A film which is too dry may be brittle and more easily 
cracked or torn. Moisture has a pronounced effect on shrinkage, 
curl, and virtually every physical property of a photographic film. 
Therefore, it is important that the influence of moisture on film be 

clearly understood. 

We frequently find that the 
amateur photographer, and some- 
times even the professional, be- 
lieves that a photographic film 
is either wet or dry and that 
there is no intermediate state. 
As long as the emulsion does not 
actually stick to the fingers, 
the film is often considered dry 
and this is responsible for some 
of the difficulties with green film. 
In actual fact, cellulose nitrate 
and acetate, as well as gelatin, 
in common with many other 
materials, exchange moisture 
vapor with their environment 
at every opportunity. Film in 
contact with dry air or wrapped 
in dry paper loses moisture ; film 
in contact with damp air gains moisture. 

The physical chemical mechanism involved in this interchange of 
moisture is rather complex and need not be discussed here. It is 
only necessary to say that from a practical point of view, the moisture 
content of film is determined almost solely by the relative humidity 
of the air with which it is in equilibrium. Theoretically, the equilib- 
rium relative humidity is the relative humidity of an atmosphere 
in which the material in question may be exposed for an infinite period 
of time without any change in moisture content. A knowledge of the 
rate of attainment of moisture equilibrium in a photographic film is of 
practical importance in many ways. 

It is worth while to emphasize that the most important controlling 




20 40 60 80 100 
RELATIVE HUMIDITY - /o 

FIG. 2. The equilibrium moisture 
content of gelatin, stripped positive 
emulsion, paper and nitrate film base 
at various relative humidities at 70 F. 



Oct., 1944 



PROPERTIES AND BEHAVIOR OF FILM 



231 



factor in determining the moisture content of photographic film as 
well as paper, gelatin, and related 
materials, is the relative humidity 
of the air and not the absolute 
humidity. This means that at 
50 F and 60 per cent RH, for 
example, film will hold more 
moisture than at 80 F and 40 
per cent RH even though the 
actual moisture content of the 
air (absolute humidity) is ap- 
proximately 32 grains per Ib of 
dry air in the first case, and 62 
grains in the second case. How- 
ever, the moisture content of 
cellulosic materials is not entirely 
independent of the dry bulb 
temperature at constant relative 
humidity. Various investiga- 
tions have shown that cotton, 6 




60 



IOO 



20 4C 

RELATIVE HUMIDITY - /o 

FIG. 3. The equilibrium moisture 
content of Eastman Safety and Nitrate 
Motion Picture Positive film base at 
various relative humidities at 70 F. 

paper, 7 and cellulose acetate 
film 8 hold slightly more moisture 
at lower temperatures when the 
relative humidity is constant. 
Nevertheless, in practice, the 
effect of a change in the dry 
bulb temperature at constant 
relative humidity on the equi- 
librium moisture content of pho- 
tographic film is negligible, com- 
pared with the effect of a change 
in relative humidity at constant 
temperature. 

The Equilibrium Moisture 
Content of Film. Fig. 2 illus- 
trates the relation between equi- 
librium moisture content and 
relative humidity for several 
common photographic mate- 
rials gelatin, positive emul- 
sion, paper, and nitrate film base. The difference in the mois- 




20 40 60 80 100 

RELATIVE HUMIDITY - /o 

FIG. 4. The equilibrium moisture 
content of Eastman Safety and Nitrate 
Motion Picture Positive emulsion 
coated film (1943) at various relative 
humidities at 70 F. 



232 



J. M. CALHOUN 



Vol 43, No. 4 



moisture content, 
per cent and 70 



Between 
per cent 



ture content of these materials at any given relative humidity 
is due to the differences in their chemical constitution and 
physical structure. It will be observed that the cellulose nitrate 
film base contains much less moisture than paper which is a form of 
natural cellulose. Positive emulsion, on the other hand, holds some- 
what more moisture than paper at any given relative humidity, 
while gelatin generally contains a still higher concentration. It 
should also be noted that all the curves are similar in shape, and each 
has 3 distinct parts. Below 20 per cent RH and above 70 per cent 
RH, the curves are relatively steep and small changes in relative 

humidity result in large changes 
in 
20 

RH the curves are almost 
straight and the change in 
moisture content for a given 
change in relative humidity is 
less. As mentioned above, this 
relationship between equilibrium 
moisture content and relative 
humidity may be considered to 
be independent of the dry bulb 
temperature for all practical 
purposes. 

Equilibrium moisture content 
versus relative humidity curves 
for both nitrate and safety 
motion picture positive film base, 
plotted on a larger scale, are shown in Fig. 3. One of the problems in 
the development of a suitable safety base is to reduce its moisture 
susceptibility to a level comparable with that of nitrate base. It 
may be noted here that safety motion picture film base which con- 
tains very little more moisture than nitrate film base can now be 
made. This is a marked improvement over the safety motion pic- 
ture film base made by the Eastman Kodak Company in 1937. In 
Fig. 4 is shown the equilibrium moisture content of nitrate and 
safety motion picture positive emulsion coated film at various 
relative humidities. 

A comparison between the moisture content of Eastman Fine-Grain 
and Regular Motion Picture Positive emulsion, and between nitrate 




20 40 60 80 
RELATIVE HUMIDITY - 



100 



FIG. 5. Typical moisture hysteresis 
curves for cellulosic materials and 
gelatin. 






Oct., 1944 PROPERTIES AND BEHAVIOR OF FILM 233 

and safety base, both at 50 per cent RH and after soaking in water, 
is given in Table 1. The ratio of the concentration of moisture in the 
emulsion to that in the base is much larger than the ratio of the 
quantity of moisture in the emulsion to that in the base. This, of 
course, is due to the approximately ten-fold greater thickness of the 
base and the difference in density. It may be seen that there is 
little difference in the moisture content of the regular and fine-grain 
emulsions at 50 per cent RH, but after soaking in water the regular 
emulsion absorbs more moisture than the fine-grain emulsion. The 
safety base has a higher concentration of moisture than the nitrate 
base at 50 per cent RH, although the quantity of moisture per unit 
area is about the same because of the difference in density of the 2 

TABLE i 

The Approximate Moisture Content of Eastman Motion Picture Positive Emulsion 

and Film Base 

Equilibrium Moisture Moisture Content After 
Content at Soaking in Water 

50 per cent at 70 F (approximate 
RH at 70 F equilibrium) 



Concen- Quantity Concen- Quantity 
tration of tration of 

of Moisture, Moisture, of Moisture, Moisture, 

Material per cent gm per ft 2 per cent gm per ft* 

Regular Emulsion (Stripped) 

(TypeJ302) 8.0 0.16 290.0 5.8 
Fine-Grain Emulsion (Stripped) 

(Type 1302) 9.0 0.18 180.0 3.6 ' 

Nitrate Base 1943 1.25 0.25 2.7 0.55 

Safety Base 1943 1.40 0.25 6.0 1.00 

types of base. After soaking in water the difference between the 
safety and nitrate base is much more marked. The last column 
of Table 1 is of particular interest in the drying of the developed 
film since the figures indicate the relative amounts of moisture which 
must be removed from the particular type of emulsion or base in 
question. 

Brief mention should be made here of a phenomenon known as 
moisture hysteresis which has been found to exist in many materials 
such as paper, 7 gelatin, 9 and cellulose derivatives. 10 The curves, in 
Figs. 2, 3, and 4 are moisture adsorption curves, that is, curves ob- 
tained by allowing very dry materials to gain moisture. However, if 
a moist material is dried, a desorption curve is obtained similar to 
that shown in Fig. 5. Hysteresis is essentially a lag in the attain- 
ment of equilibrium, so that a higher moisture content is found if a 



234 



J. M. CALHOUN 



Vol 43, No. 4 



given relative humidity is approached from above rather than from 
below. 

The Rate of Swell of Film in Water. When a photographic film 
is immersed in water, both the base and emulsion absorb moisture 



300 



280 



260 



240 



220 



200 



180 



160 



140 




TIME - MINUTE 



FIG. 6. The rate of moisture absorption of Eastman Motion Picture 
Positive emulsion (1301, Regular; 1302, Fine-Grain emulsion stripped from 
the base), and film base in water at 70 F, starting from equilibrium at 50 
per cent RH for the emulsion and oven-dry for the base. 



and begin to swell. The base swells in all 3 dimensions, but the 
emulsion swells principally in a direction at right angles to the plane 
of the film. This is due to the fact that the emulsion is firmly at- 
tached to the base and, therefore, its swelling is largely restricted 
to the vertical direction. 

Fig. 6 shows that emulsions not only absorb more moisture than 



Oct., 1944 



PROPERTIES AND BEHAVIOR OF FILM 



235 



film base when immersed in water but do so more rapidly. In 5 
min, for example, the emulsion absorbs 2 to 3 times its weight of 
moisture, whereas the base absorbs only a few per cent of its weight 
of moisture. This means that if a film is immersed in water and 
then removed before the base is completely swollen, moisture may 
diffuse from the wet emulsion into the base causing the latter to 




800 



100 



1000 



TIME - MINUTES 



FIG. 7. The rate of swell of gelatin (attached to film support) and Eastman 
Motion Picture Positive film base in water at 70 F, starting from equilibrium 
at 50 per cent RH. 

continue swelling. Fig. 6 also shows that Eastman Fine-Grain 
Positive emulsion (Type 1302) absorbs less moisture when im- 
mersed in water than the Regular emulsion (Type 1301), and that 
it does so more slowly. A comparison of safety and nitrate film base 
in turn shows that the safety base not only picks up more moisture 
than the nitrate base, but does so more rapidly. 

Fig. 7 gives the rate of vertical swell of gelatin (coated on film 
support) and the rate of lateral swell of nitrate and safety film base 



236 J. M. CALHOUN Vol 43, No 4 

in water starting from 50 per cent RH. The change in dimension, 
in general, parallels the change in moisture content. The extremely 
rapid swelling of the gelatin compared to the film base is apparent. 
In 5 min the gelatin swells more than ten-fold in thickness, whereas 
the film base swells only a small fraction of 1 per cent in length. The 
safety base swells to a greater extent than the nitrate base and does 
so more rapidly, as would be expected from the difference in their 
rates of moisture absorption. It is conceivable that 2 different films 
might show the same degree of expansion when fully swollen in 
water, and yet have different swelling rates. This would be impor- 
tant in processing where the immersion time is relatively short, 
and the faster swelling film would reach a greater extension. 

The Rate of Drying of Film. The rate of drying of wet film after 
development is very important to the motion picture laboratory. 
When the film surface is wet, the rate of evaporation of moisture 
from the film is essentially the same as the rate of evaporation from 
a free water surface. In the absence of radiant heat, the rate of 
drying of film by air flowing parallel to the surface is constant as 
long as the film surface is wet. Under these conditions, the rate of 
drying may be expressed by the following equation, which is merely 
a modification of the standard evaporation formula 11 

W 
T = k (Ps - Pa}V** (I) 

where T = drying time, min 

W = weight of water in film, gms per ft 2 

Ps = vapor pressure of water at the surface temperature (wet bulb), 

mm Hg 

Pa = vapor pressure of water in the air (dew point) , mm Hg 
V = air velocity parallel to the surface, ft per sec 
k = a constant 

This equation shows that the time to sensible dryness is reduced 
by: 

(1) Decreasing the water content of the wet film by hardening or by the use 
of a squeegee. 

(2) Increasing the difference between the wet bulb temperature and the dew 
point of the air. 

(3) Increasing the air velocity. 

This formula has been found to apply very well to the drying of 
film within the limitations specified. However, there are a number 
of practical considerations in the drying of developed film which 
limit the conditions which may be selected. For example, the dry 






Oct., 1944 PROPERTIES AND BEHAVIOR OF FILM 237 

bulb temperature must not be too high while the film is still wet or 
the emulsion may be softened undesirably. Very rapid drying 
under extreme conditions may lead to various film troubles, which 
are discussed in a later section. 

The Rate of Conditioning of Film. The rate at which a film at- 
tains moisture equilibrium, or the rate of conditioning, is an entirely 
different problem from the rate of drying of a wet film. In Fig. 8 we 
have plotted the change in moisture content by weight (expressed 
as a per cent of the total change) for motion picture positive 
film initially in equilibrium with air at 78 per cent RH against the 
time exposed to an atmosphere at 21 per cent RH. It will be ob- 
served that the change in moisture content is very rapid at first, 
the rate of change decreasing as equilibrium is approached. This 
graph also shows the relative rates of conditioning of stripped emul- 
sion and uncoated nitrate base which are particularly interesting. 
The stripped emulsion conditions much more rapidly than the base, 
reaching 90 per cent of equilibrium in a minute or two as compared 
with about 40 min for the base under the conditions of the experi- 
ment. This difference is due to the greater thickness of the base 
as well as to the differences in chemical constitution and physical 
structure between the 2 materials. 

A number of extrinsic factors affect the rate of conditioning of 
film the air velocity, the manner of air application, the temperature, 
the relative humidity difference, and so forth. Attempts have been 
made to develop an empirical formula which would relate these vari- 
ables and enable one to compute the rate of conditioning of film under 
various circumstances. However, no simple way of doing this has 
yet been found so that it is necessary to determine by trial the opti- 
mum manner for conditioning film with a given piece of equipment. 

The Processing of Motion Picture Film. The application of 
some of the principles just described may be illustrated in the proc- 
essing of motion picture film. In the continuous machine the film 
is generally immersed in the developer, fixing bath, and wash water 
for a total of 20 to 35 min, depending on the type of film and the 
processing conditions employed. By the time the film leaves the 
wash water, the emulsion is completely swollen, but the base only 
partly swollen. This is due to the difference in rates of swelling be- 
tween the base and emulsion (cf. Figs. 6 and 7). Surface water is 
then removed from both sides of the film by a squeegee. 

In the first stages of drying, moisture from the wet emulsion 



238 J. M. CALHOUN Vol 43, No. 4 

diffuses into the base, which may even continue to swell slightly. 
This retards the drying of the base. The rate of drying of the 
emulsion is greater than that of the base, because moisture diffuses 
more easily from the interior to the surface in the case of the former. 
Therefore, in spite of the larger quantity of moisture originally 
present, the emulsion will generally dry sooner than the base. Once 
the emulsion is sensibly dry it will condition more rapidly than the 
base to the relative humidity of the drying air. Some of the diffi- 

TABLE 2 

The Approximate Moisture Content of Various 'Eastman Nitrate Motion Picture 
Films in the Drying Cabinet of a Processing Machine 

Time to 

Sensible Moisture Content Moisture Content 

Type Dryness, After Squeegee When Reeled 

Film No. min per cent gm per ft per cent gm per ft 

Background X Panchro- 
matic Negative 1230 18.2 29.0 0.96 3.34 0.069 

Plus X Panchromatic 

Negative 1231 20.9 33.0 1.00 3.44 0.070 

Super XX Panchromatic 

Negative 1232 25.6 33.0 1.14 3.66 0.088 

Fine-Grain Panchro- 
matic Duplicating 
Negative 1203 9.5 16.8 0.45 2.58 0.058 

Release Positive 1301 8.1 17.3 0.47 2.68 0.061 

Fine-Grain Release Posi- 
tive 1302 5.4 12.2 0.31 2.76 0.064 

Fine-Grain Duplicating 

Positive 1365 5.4 11.0 0.27 2.34 0.057 

Temperature of wash water, 68 F. 
Squeegee nozzle pressure, 30 Ib per in. 2 
Drying air, 70 F, 55 per cent RH. 

culties which may be encountered if film is reeled while the emulsion 
is dry, but the base still moist, are discussed by Talbot. 1 

In Table 2 the time to sensible dry ness is given for various Eastman 
nitrate motion picture films developed in a typical commercial proc- 
essing machine. The regular negative type films require longer to 
dry than the positive films, because the negative emulsion is thicker 
and, therefore, holds more moisture (W in Eq (1) is larger). The 
moisture content of the film in per cent, and in grams per linear foot 
of 35-mm film, just after the squeegee, and at the point of reeling, is 
also given in Table 2. However, it should be remembered that 



Oct., 1944 



PROPERTIES AND BEHAVIOR OF FILM 



230 



these data apply only to a particular case, and will vary with the 
type of film, the nature of the processing machine, and the drying 
conditions employed. 

Motion picture film after processing should be neither overdried 
nor underdried. Film which is overdried may have too high a curl, 
and give a "spoky" roll when wound. 12 Film which is insufficiently 
dried may be tacky, which (in the case of release prints) aggravates 
the various troubles characteristic of green film. 13 Under certain 
conditions, moist film also has a greater tendency to go "in-and-out 
of focus" when projected. 14 




234 



6 8 10 20 30 40 60 
TIME - MINUTES 



200 300 



FIG. 8. The rate of conditioning of Eastman Nitrate 
Motion Picture Positive film from 78 per cent RH to 
21 per cent RH at 70 F. Unknown low air velocity, 
probably under 1 ft per sec. 



In the light of information available at the present time, it is 
generally recommended that motion picture film be dried in air 
having the relative humidity desired at equilibrium. It is preferable 
to dry negatives in air at about 60 per cent RH, because of the 
danger of producing static marks on the positive in printing if the 
negative is too dry. Positives, on the other hand, should be dried in 
air at about 40 per cent RH to minimize tackiness and reduce the 
tendency of the film to go "in-and-out of focus" when projected. 
In either case, sufficient time should be allowed to bring the base as well 
as the emulsion to approximate equilibrium with the drying air. In 
laboratories where it is impractical to have 2 different sets of drying 
conditions, a choice of about 50 per cent RH is probably the best 



240 



J. M. CALHOUN 



Vol 43, No. 4 



compromise, Where possible, the drying temperature should not 
be allowed to exceed 85 F. 

THE MECHANICAL PROPERTIES OF FILM 

The mechanical properties of motion picture film, such as tensile 
strength, elongation, folding endurance, tearing resistance, and 
brittleness are important because of the severe wear that the film 



40 



30 



20 



LJ 



10 




FIG. 



5 10 15 

LOAD - I0 3 LBS/IN 2 

. Typical load-elongation diagram 
for cellulose derivative films. 



must withstand, particularly in the case of release positives subjected 
to repeated projections. The elastic and plastic properties of the 
film, such as modulus of elasticity and cold flow, are equally impor- 
tant, not only from the point of view of wearing quality, but also 
as they affect the dimensional stability of the film and its suscepti- 
bility to curl and various other film distortions. 

Theoretical. It is necessary here to describe briefly the mechani- 
cal behavior of plastic materials, of which film base is typical. If 
any material under load (either tension or compression) undergoes 
a deformation which is independent of the rate of loading and dis- 



Oct., 1944 



PROPERTIES AND BEHAVIOR OF'FILM 



241 



appears rapidly and completely when the load is removed, the de- 
formation is said to be elastic. When recovery after removal of the 
load is not complete, the nonrecoverable deformation is said to be 
plastic. In cases where the deformation is directly proportional to 
the load and is recoverable, the following relation (Hooke's Law) 
holds: 

F = E^ (2) 



where F = the load applied per unit area 
L = the length of the sample 
E = a constant (the modulus of elasticity) 




TIME - HOURS 

FIG 10. Typical flow (or creep) and recovery diagram for cellulose 
derivative films under constant tension. 



The modulus of elasticity (or Young's Modulus for a material under 
tension) is the slope of the straight line portion of the load-elongation 
curve (Fig. 9) for small loads, and is important as a measure of the 
resistance the material offers to deformation under stress. 

In the case of plastic materials such as cellulose nitrate and 
acetate film base, the load-elongation curve is a function of the 
rate of loading, since plastic as well as elastic deformations occur 
even at very small loads. The point at which the elongation in- 
creases rapidly for a small increase in load is called the yield value 
and is of considerable practical importance in motion picture film, 
since it is the point at which the material begins to give way. 



242 J. M. CALHOUN Vol 43, tfo. 4 

If a small constant tension is applied to a strip of film and the 
elongation measured against time, a complicated series of phenom- 
ena occur as illustrated in Fig. 10. Following the first instantane- 
ous elastic extension, elongation does not cease, but continues at a 
gradually decreasing rate. This is due to a combination of delayed 
elasticity and plastic deformation, and the material appears to flow 
or creep. If the load is removed at the end of a given time, there is 
first an instantaneous elastic contraction corresponding to the origi- 
nal instantaneous elastic extension. The film then continues to 
contract, a behavior called creep recovery. However, the film may 
not regain its original size or form, even in a very long time. The 
portion of the creep which is recoverable has been termed delayed 
elasticity or primary creep, and the portion which is not recoverable 
has been termed plastic flow, secondary creep, or more commonly, 
cold flow* A material which has undergone cold flow is said to 
have taken a permanent set. 

Plastic behavior of the type described above is important in 
motion picture film, because of the permanent deformations or dis- 
tortions which may result from the application of stress during stor- 
age, handling, processing, or projection. The magnitude of the cold 
flow which may occur in a given film increases with increase in the 
load applied, the time during which it acts, the temperature, and the 
moisture content of the film. If the temperature of a piece of film 
under tension is reduced before the load is removed, creep recovery is 
retarded or prevented. This phenomenon has already been referred 
to as the "freezing-in of strain." If the film is reheated at some 
later time after removal of the load, recovery of primary creep will 
occur and produce a shrinkage. For a more detailed description of 
the elastic and plastic behavior of materials of this type, the reader 
is referred elsewhere. 2 ' 5 - 15 - 16 

* There is some lack of uniformity in the literature concerning the terminology 
employed for the various types of deformation which plastic materials exhibit 
under load. Both the recoverable and nonrecoverable portions of creep are some- 
times included in the term, plastic flow. This may be due to the fact that an 
analogy is sometimes drawn between recoverable creep and the behavior of a 
model consisting of both elastic and viscous elements connected in parallel. 2 - 15 
However, recoverable creep is more logically considered as an elastic deformation 
in the sense that it is eventually recovered, although it is a delayed, or imperfect 
elasticity. We prefer to reserve the terms plastic flow and cold flow for the non- 
recoverable creep. Leaderman 5 overcomes this difficulty by the use of the terms 
primary creep (recoverable) and secondary creep (nonrecoverable) . 



Oct., 1944 



PROPERTIES AND BEHAVIOR OF FILM 



243 



The Strength, Elongation, Modulus of Elasticity, and Cold Flow 
of Film. In Table 3 are recorded some of the mechanical properties 
of nitrate and safety motion picture positive film base compared 
with metals and rubber. The tensile strength and elongation 
measurements on the film base were made with a Schopper dynamom- 
eter operating at a speed of 100 mm per min. The values ob- 
tained are not absolute values, but depend somewhat on the rate 
of testing because of the tendency of the material to exhibit plastic 
flow. Young's modulus for the film base was determined by 
quickly measuring the elongation produced by the application of a 
small tension below the yield value. The cold flow or permanent 
set was determined by measur- 
ing the residual extension re- 
maining after the load and re- 
covery cycle specified. 

The data show that both 
nitrate and safety film base lie 
between steel and rubber in 
tensile strength, elongation at 
break, and Young's modulus. 
The nitrate base has a higher 
tensile strength, lower elonga- 
tion at break, higher Young's 
modulus, and lower cold flow 
than the safety base. The dif- 
ferences between the lengthwise 
and widthwise properties are due 
to the part ally oriented struc- 
ture of the film base produced 
by slight stretching during 

manufacture. The film is slightly stronger in the direction of ori- 
entation (lengthwise) and is more easily stretched widthwise. For 
this reason, Young's modulus is highest lengthwise and cold flow is 
highest widthwise. 

The effect of relative humidity and temperature on the mechanical 
properties of motion picture film is very important in practice. 
Fig. 11 demonstrates that an increase in the moisture content of 
film reduces the tensile strength and increases the elongation at 
break. Fig. 12 shows that an increase in moisture content reduces 
Young's modulus and increases the degree of cold flow. These 




20 40 60 80 

RELATIVE HUMIDITY - 9b 



15 



FIG. 11. The effect of relative 
humidity on the ultimate tensile 
strength and elongation at break of 
Eastman Nitrate Motion Picture 
Positive film in the lengthwise direc- 
tion at 70 F. 



244 



J. M. CALHOUN 



Vol 43, No. 4 



effects are apparently due to a plasticizing action of the moisture 
between the molecules of the base, and demonstrate that a moist 
film is weaker and is more easily stretched or distorted than a dry 
film. This should be borne in mind in the handling of film in proc- 
essing machines. 

The effect of temperature at constant relative humidity on the 
mechanical properties of film is, in general, in the same direction 
as the effect of an increase in relative humidity at constant tem- 
perature. Heat, like moisture, makes the film base softer and more 

pliant. This reduces the tensile 
strength and modulus of elas- 
ticity, and increases the tendency 
to plastic flow. Therefore, film 
is particularly susceptible to 
various distortions at elevated 
temperatures. However, it 
should be remembered that an 
increase in temperature is gener- 
ally accompanied by a decrease 
in relative humidity and vice 
versa, so that the effect of re- 
duced moisture may partially 
compensate for the effect of 
heat. 

The Folding Endurance and 




FIG. 12. The effect of relative 
humidity on the Young's modulus 
and cold flow of Eastman Nitrate 
Motion Picture Positive film in the 
lengthwise direction at 70 F. Load 
for cold flow test, 1900 Ib per in. 2 ; 
time loaded, 7 days; recovery time, 
24 hr. 



Tearing Resistance of Film. 
The folding endurance and 
tearing resistance of nitrate and 
safety motion picture film base 
are also recorded in Table 3. The folding endurance (number of 
folds) was determined with the Schopper fold testing machine, 
which folds the sample sharply back and forth until it breaks. 
The tearing resistance was measured with the Elmendorf tear 
tester. A tear is first started by hand, then a weighted disk 
revolves which continues the tear, and an indicator measures the 
tearing resistance. It may be seen that the nitrate film base has 
a higher folding endurance and a higher tearing resistance than 
the safety base. The tearing resistance of film base is lowest in the 
lengthwise direction owing to its partially oriented structure (that 
is, the film tears more easily along the "grain"). The increased 






Oct., 1944 



PROPERTIES AND BEHAVIOR OF FILM 



245 



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246 



J. M. CALHOUN 



Vol 43, No. 4 



folding endurance and tearing resistance of the film at high relative 
humidities are illustrated in Fig. 13. This is apparently due to the 
fact that the film base is softer and more limp when moist, and it 
tends to "give" rather than rupture. 

The mechanical properties described in the above sections affect 
the performance of film on continued projection, and indicate some 
of the reasons for the supremacy of nitrate base in the motion picture 
field. Nevertheless, safety film has made rapid strides in recent 
years, and its physical properties now approach more closely to those 

of nitrate than was formerly the 
case. This is illustrated in Table 
3 with the comparison between 
Eastman Safety Motion Picture 
film base manufactured in 1937 
and that manufactured in 1943. 
The improvement in the safety 
base is particularly marked in 
the case of folding endurance. 
Mechanical tests of this nature 
give an indication of what may 
be expected from a given film in 
use, although they are not a 
direct measure of practical per- 
formance. These laboratory 
tests also help to give a clearer 




60 80 

HUMIDITY - 96 



FIG. 13. The effect of relative hu- 
midity on the folding endurance and 
tearing resistance of Eastman Nitrate 
Motion Picture Positive film in the 
lengthwise direction at 70 F. 



understanding of the behavior of 
the film, and are useful in manu- 
facturing control to make sure that the highest possible quality is 
maintained. 

Brittleness. Brittleness is another important physical property 
of a photographic film. Difficulty from brittleness is generally en- 
countered only at low relative humidities or at very low tempera- 
tures. When a piece of film is sharply flexed or bent, the surface 
on the inside of the bend is compressed, while that on the outside is 
stretched. Therefore, a crack generally starts on the outside of the 
bend. Emulsion coated film is more brittle than the base alone, 
partly because the emulsion itself is more brittle which increases 
the chance of a break starting. Film is more likely to break if bent 
with the emulsion side out than if bent with the emulsion side in 
because in the first case the emulsion is under tension, whereas in 



Oct., 1944 



PROPERTIES AND BEHAVIOR OF FILM 



247 



the second case it is under compression. When the film is bent with 
the emulsion side out, the emulsion adhering tightly to the base 
tends to prevent the outer surface of the latter from stretching. 
Once the emulsion cracks the stress is localized and the base is much 
more likely to rupture. 

If a film is bent slowly there is less chance of a break than if it is 
bent rapidly, because there is more time for elastic or plastic defor- 
mations to occur, which help to dissipate the stress. For this 
reason, film breaks due to brittleness under adverse conditions are 
more likely to occur in high-speed equipment. The design of motion 



020 




20 40 60 80 

RELATIVE HUMIDITY -96 



_40 +40 +80 

TEMPERATURE -F 



FIG. 14. The effect of relative humidity and temperature 
on the vise brittleness of undeveloped Eastman Motion Picture 
film in the lengthwise direction. (Dotted line indicates double 
film thickness corresponding to minimum brittle point.) 

picture equipment should exclude sharp bends in the film travel, 
particularly with the emulsion side out, whenever possible. 

The film brittleness test we have used consists of breaking a loop 
of film, emulsion side out, between the jaws of a vise closed at a 
uniform speed. The distance between the jaws of the vise at the 
instant the film cracks is a measure of the brittleness of the film. Fig. 
14 illustrates the effect of relative humidity and temperature on the 
"vise brittleness" of nitrate and safety motion picture film. The 
measurements at 70 F were made in air-conditioned rooms. For the 
subzero temperatures, it was necessary to precondition the film 
samples to the desired relative humidity at 70 F, seal them in small 
individual metal containers, and then cool to the desired tempera- 
ture. The tests were then made quickly (in less than a minute) in a 
cold room where the humidity was not controlled. 



248 J. M. CALHOUN Vol 43, No. 4 

It may be seen in Fig. 14A that the brittleness of motion picture 
film at 70 F is virtually negligible above 20 per cent RH, but in- 
creases rapidly as the relative humidity is reduced below 20 per cent. 
There is very little difference in brittleness between the present 
Eastman nitrate and safety motion picture film although the safety 
film made a number of years ago was considerably more brittle than 
the nitrate. 

Fig. 14B shows that the brittleness of motion picture film in- 
creases as the temperature is lowered. At about 25 F and 60 per 
cent RH the ,film has the same degree of brittleness as at 70 F and 
14 per cent RH. The effect of subzero temperatures on the brittle- 
ness of film is of interest where motion pictures must be taken in 
arctic regions or at high altitudes. Attention is drawn to the fact 
that relative humidity has an important bearing on the brittleness 
of film even at temperatures below the freezing point of water. Ap- 
parently the moisture in the film does not crystallize at these tem- 
peratures, but remains in an amorphous or supercooled liquid state, 
and continues to plasticize the emulsion and film base. This is 
probably the reason that more trouble from brittleness is not en- 
countered in the arctic, where the outside relative humidity is gener- 
ally high. Nevertheless, precautions should be taken to prevent 
film from drying out prior to use at low temperatures. Additional 
care should be given to the handling of film and the proper operation 
of equipment at either low relative humidities or low temperatures. 

Tackiness. Although tackiness is not a mechanical property of 
film it is discussed in this section for convenience. The tendency of 
film to stick to itself, or to metal parts of cameras or projectors, 
seldom occurs except at very high humidities, particularly when 
warm. Under these conditions the emulsion may become somewhat 
soft and spongy and in extreme cases plasticizer may diffuse out of 
the base and cause tackiness. The most difficulty from tackiness 
in practice occurs with green prints which have been insufficiently 
dried. The emulsion tends to stick in the projector gate, especially 
if the latter is warm. This builds up tension on the film and may 
cause a tear or break. Particles of emulsion may also pile up in the 
gate as a hard, horny deposit and cause trouble. Adequate drying 
after processing tends to reduce this difficulty, but in any case new 
prints should be waxed' or lubricated in some way before the first 
projection. 



Oct., 1944 PROPERTIES AND BEHAVIOR OF FILM 249 

DIMENSIONAL CHANGES IN FILM 

The dimensional changes which occur in motion picture film with 
changes in humidity, temperature, and age are important because 
they affect the distance between perforations (perforation pitch). 
Camera, printer, and projector sprockets are designed to accommo- 
date film having a definite longitudinal and transverse perforation 
pitch and any marked change in the dimensions of the film causes 
more or less serious trouble. In the past only lengthwise shrinkage of 
motion picture film has been considered of importance, but of late 
certain photogrammetric applications have aroused interest in 
widthwise shrinkage which is not necessarily the same. Therefore, 
in the discussion that follows some attention will be given to differ- 
ences between lengthwise and widthwise shrinkage. 

In any discussion of film shrinkage it is important to distinguish 
between the different types of dimensional change which may occur. 
'Dimensional changes in film are of 2 types temporary or reversible, 
and permanent or irreversible. Temporary dimensional changes 
are caused by thermal expansion or contraction resulting from change 
in temperature, and humidity expansion or contraction resulting from 
change in moisture content. Permanent dimensional changes are 
due to a variety of causes. The magnitude of the dimensional 
changes which take place in a given film depends largely on the 
composition of the base, the treatment it received during manufac- 
ture, and the type and thickness of emulsion employed. Both tem- 
porary and permanent dimensional changes may occur simultane- 
ously, and both may be complicated by hysteresis and related phenom- 
ena. The size of a piece of film at any instant is the resultant 
of all these effects. 

The shrinkage measurements described in this paper were made in 
air-conditioned laboratories at accurately controlled temperature 
and relative humidity, using the pin-gage method described in the 
Bureau of Standards Research Paper No. 1051. 17 The humidity 
coefficient of linear expansion (sometimes called humidity ampli- 
tude) was determined by first measuring samples conditioned at 
20 per cent RH at 70 F approached from above, and then remeasur- 
ing after conditioning at 70 per cent RH at 70 F approached from 
below. The change in length was then calculated for a 10 per cent 
relative humidity interval. This procedure does not exclude errors 
due to hysteresis which amount to approximately 0.005 per cent of 
the dimension for every 10 per cent change in relative humidity. 



250 J. M. CALHOUN Vol 43, No. 4 

This means that the values reported in this paper for the humidity 
coefficient of linear expansion of film are too small by about 0.005 per 
cent of the dimension per 10 per cent RH. Permanent shrinkage 
was determined by making the initial and final measurements at 
the same conditions of relative humidity and temperature, generally 
50 per cent RH at 70 F. 

Temporary Expansion and Contraction. Photographic film ex- 
pands when heated and contracts when cooled at constant relative 
humidity. The thermal coefficient of linear expansion of most films 
is approximately 5 X 10~ 5 in. per in. per degree F (0.05 per cent per 
10 F) at normal temperatures. However, in practice when the tem- 
perature increases the relative humidity generally drops, and since 
moisture has a greater effect than heat, the net result may be a con- 
traction rather than an expansion. 

The humidity expansion or contraction of film is much more im- 
portant than purely thermal expansion from a practical point of view.' 
When the film base takes up moisture it swells, and when it loses 
moisture it contracts. The magnitude of this effect is greater with 
emulsion coated film than with uncoated base because the emulsion 
has a greater tendency to contract than the base as the relative 
humidity is lowered (cf. Table 5). The base is compressed slightly 
by the emulsion under these conditions, thus increasing the con- 
traction of the film at low relative humidities. The humidity ex- 
pansion or contraction of film follows the change in moisture content, 
so that the dimensions at any given instant vary with the relative 
humidity of the atmosphere and the rate of conditioning of the film. 

The magnitude of the humidity coefficient of linear expansion 
of common motion picture films varies from 0.04 per cent to 0.12 per 
cent of the dimension per 10 per cent change in relative humidity 
at 70 F. The change in dimension with change in equilibrium rela- 
tive humidity is very nearly linear between 20 per cent and 70 per 
cent RH, but is somewhat greater below 20 per cent and above 70 
per cent RH. As already mentioned, hysteresis plays a part in 
humidity dimensional changes, the film being slightly shorter if 
equilibrium at a given relative humidity is approached from below 
than if it is approached from above (cf. Fig. 5). 

The thermal expansion and humidity expansion of photographic 
films manufactured in the manner we have described, are generally 
from 10 per cent to 40 per cent greater in the width wise direction 
than in the lengthwise direction. This is caused by the partial orien- 



Oct., 1944 PROPERTIES AND BEHAVIOR OF FILM 251 

tation of the cellulose nitrate or acetate molecules in the base in the 
machine direction. When the molecules are aligned it is evidently 
easier to increase the distance between them (by thermal agitation or 
by the introduction of moisture) in a direction perpendicular to the 
alignment. In practice this means that changes in temperature and 
humidity will have a slightly greater effect on transverse pitch than 
on longitudinal pitch. 

Permanent Dimensional Changes. Photographic film undergoes 
a gradual but continuous permanent shrinkage throughout its life, 
at a rate which depends on the type of film and the conditions under 
which it is used or stored. The permanent shrinkage of a photo- 
graphic film is due principally to the following causes : 

(1) Loss of residual solvent or volatile material other than moisture. Shrinkage 
due to this cause is increased by heat and moisture and reduced by preventing 
free access to the air. The effect of moisture is two-fold it accelerates diffusion 
of solvents from the interior of the base and also renders the emulsion more per- 
meable. (Dry gelatin is an effective barrier to many solvents.) Shrinkage result- 
ing from the loss of volatile material from the base is greatest in the widthwise di- 
rection because of the orientation of the cellulose nitrate or acetate molecules. 

(2) Plastic flow of the base. The compressive force of the emulsion upon the 
base results in a certain amount of plastic flow or permanent shrinkage. Dimen- 
sional changes of this type are increased by heat because the base is softer and 
more plastic at higher temperatures. Moisture also increases the plasticity of the 
base, but it reduces the contraction of the emulsion, and the latter has the greater 
effect. Consequently, an increase in relative humidity at constant temperature 
generally decreases this type of shrinkage. Plastic flow of the base may also be 
produced by stretching in -handling or processing which, of course, will result in an 
extension rather than shrinkage. Dimensional changes of this type are increased 
by heat, moisture, the tension applied, and the time during which it acts. Shrink- 
age or stretch caused by plastic flow of the base is slightly greater in the width- 
wise direction (cf. Table 3). 

(3) Release of strain or recovery from deformation. If film base is stretched dur- 
ing manufacture under conditions which do not permit reorientation of the cellu- 
lose nitrate or acetate molecules, deformation or creep occurs resulting in a length- 
wise extension and a widthwise contraction. Rapid cooling retards recovery of 
the deformation (primary creep) due to "freezing-in of strain." This strain may 
be released at some time during the life of the film with a consequent lengthwise 
shrinkage and widthwise expansion. Where such a strain exists, the rate of re- 
covery is increased by both heat and moisture. 

It will be seen from the above that the shrinkage of photographic 
film is extremely complex. Several different processes are going on 
simultaneously, and each is affected in a different manner by heat, 
moisture, and other factors. It is not always easy to predict how a 



252 J. M. CALHOUN Vol 43, No. 4 

given film will shrink when subjected to unknown conditions of 
storage and handling. 

The largest portion of the permanent shrinkage of most motion 
picture films results from the first of the above causes, that is, loss 
of volatile material from the base. The exact magnitude of the 
dimensional changes produced by compression by the emulsion, and 
release of strain in the base are difficult to determine because they 
are generally masked by the larger effects of solvent loss. With some 
low-shrink films, the shrinkage of the base alone may be compared with 
the shrinkage of the emulsion coated film to obtain an estimate of the 
plastic compression in the latter? This is not possible with ordinary 
motion picture films because the emulsion influences the rate of sol- 
vent loss which masks the effect of plastic flow of the base. Com- 
pression by the emulsion and release of strain in the base are gener- 
ally of secondary importance in the shrinkage of motion picture film, 
except in special cases where a high degree of dimensional stability 
is required, or where extremely severe storage conditions are en- 
countered. 

Although temporary dimensional changes in a motion picture 
film are always greatest in the widthwise direction, permanent shrink- 
age may be greatest in either the lengthwise or widthwise direction, 
depending on which of the 3 causes described above predominates. 
In cases where the release of strain is large, the permanent shrinkage 
is greatest in the lengthwise direction. However, since loss of 
volatile material predominates in most motion picture films, per- 
manent shrinkage is generally greatest in the widthwise direction 
(cf. Table 4). 

The Shrinkage of Raw Stock. The shrinkage of motion picture 
film prior to exposure is generally small, where the film is kept in 
tight rolls in closed metal containers which retard the loss of both 
solvents and moisture. In the case of unexposed nitrate motion pic- 
ture film in 1000-ft rolls in taped cans which have not been opened, 
the actual shrinkage (temporary and permanent) seldom reaches 
0.1 per cent in 6 months at 70 F. However, where cardboard boxes 
were temporarily substituted for cans during the war a somewhat 
higher shrinkage was encountered. The necessity of using rubber 
substitutes in adhesive tape during the war has also resulted in 
slightly greater shrinkage. 

Film in 16-mm X 100-ft rolls wound on cores shrinks more rapidly 
than the same film in 35-mm X 1000-ft rolls, because there is a 



Oct., 1944 



PROPERTIES AND BEHAVIOR OF FILM 



253 



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254 



J. M. CALHOUN 



Vol 43, No. 4 



smaller distance for the moisture and solvents to travel from the 
interior of the roll. For the same reason, 16-mm film wound on cores 
will shrink more rapidly than the same film wound on flanged metal 
spools. Some of the older Eastman 16-mm safety reversal films on 
100-ft spools in taped cans shrink approximately 0.25 per cent in 6 
months at 70 F, but the present safety reversal films shrink some- 
what less under the same conditions. In cases where the storage 
conditions are more severe, a higher shrinkage will be encountered. 



0.6 




10 



20 30 40 

TIME - WEEKS 



50 



FIG. 15. The effect of free access to the air on the 
rate of shrinkage of processed Eastman Nitrate Motion 
Picture Positive film in the lengthwise direction at 50-65 
per cent RH at 70 F. (The rolls in taped cans were 
opened for each measurement which slightly increases 
the rate of shrinkage.) 

Once a can of film is opened 2 things happen the film starts to 
approach equilibrium with the relative humidity of the air, and 
shrinkage due to the loss of solvents is accelerated. Consequently, 
film which has been opened for a few days, especially in a dry atmos- 
phere, may have a somewhat shorter pitch than expected. The use 
of film under these conditions for the design of 16-mm camera sprock- 
ets has sometimes led to errors, particularly in the case of special 
cameras for which pitch is unusually critical. The sprocket pitch 
should be such that film stored under normal conditions will mesh 
properly when fresh from the can. 

Processing Shrinkage. Both nitrate and safety base films swell 



Oct.. 1944 



PROPERTIES AND BEHAVIOR OF FILM 



255 



during development and shrink back again during drying. Most 
films also undergo a small permanent shrinkage during processing. 
However, if the film is not brought to equilibrium with air at the 
same relative humidity after development as it was before, the per- 
manent processing shrinkage may be completely masked by the 
temporary expansion or contraction due to change in relative hu- 
midity. This frequently happens in the case of motion picture film, 
which at the time of perforating may have a moisture content 
equivalent to that at equilibrium with air between 50 per cent and 



08 




10 



20 30 40 

TIME - WEEKS 



50 



FIG. 16. The effect of relative humidity on the rate of 
shrinkage of processed Eastman Nitrate Motion Picture 
Positive film in the lengthwise direction at 70 F. (Film in 
strips having free access to air.) 



60 per cent RH. If the film is removed from the drying cabinet 
after processing with a moisture content equivalent to that at 
equilibrium with air between 70 per cent and 80 per cent RH, the 
permanent shrinkage of the raw stock plus the processing shrinkage 
will be masked by the humidity expansion, so that the pitch of the 
film may even be slightly longer than the standard. 

The Effect of Storage Conditions on the Shrinkage of Film. 
After development, photographic film continues to shrink at a de- 
creasing rate throughout the remainder of its life. The degree of 
permanent shrinkage which occurs depends on the type of film and 
the treatment it receives. The effect of several extrinsic variables 



256 



J. M. CALHOUN 



Vol 43, No. 4 



on the permanent shrinkage of film during aging after development 
is illustrated in Figs. 15, 16, and 17. A comparison of the permanent 
shrinkage of strips of film suspended freely in circulating air, and 
film wound in tight rolls in untaped, and in taped cans is shown in 
Fig. 15. Free access to the air enables solvents and other volatile 
material to diffuse out of the film more easily and, therefore, accel- 
erates shrinkage. Fig. 16 shows the effect of relative humidity at 
constant temperature, on the rate of shrinkage of strips of nitrate 



1.4 




~0 I 2 3 4 

TIME - MONTHS 

FIG. 17. The effect of temperature on the rate of shrinkage of 
processed Eastman Safety 16-mm Reversal film (Type No. 4, 
Table 4) in the lengthwise direction at 20 per cent RH. (Film in 
strips having free access to air.) 



motion picture positive film hung in circulating air. As mentioned 
previously, moisture aids the diffusion of solvents through both the 
base and the emulsion, so that the film shrinks more rapidly at 
higher relative humidities. Fig. 17 illustrates the effect of tempera- 
ture at constant relative humidity on the rate of shrinkage of East- 
man Safety 16-mm Reversal Film. Heat drives out some of the re- 
sidual volatile material from the film base, thus accelerating shrink- 
age. 

The influence of the various storage variables on the rate of shrink- 
age described above applies qualitatively to the majority of motion 



Oct., 1944 PROPERTIES AND BEHAVIOR OF FILM 257 

picture films. Consequently, where low shrinkage is desired over a 
period of time, the film should be stored in tight rolls in well-taped 
cans at low temperatures (50 F, for example) and at moderate rela- 
tive humidities (40 per cent to 50 per cent RH). 

Although a storage relative humidity below 40 per cent would be 
preferable from the point of view of reducing permanent shrinkage, 
this is not recommended for several reasons. Film tends to become 
brittle, and curl becomes excessive at low relative humidities. Al- 
though negatives may be stored safely at a relative humidity around 
40 per cent, they should be brought to equilibrium with air at a 
relative humidity of 60 per cent to 70 per cent at the time of printing 
to prevent static discharges on the raw positive. If developed rolls 
must be stored in untaped cans or cardboard boxes, it is more im- 
portant that the film at the time of winding be in equilibrium with 
the relative humidity most likely to be encountered in the storage 
atmosphere. This is necessary to prevent differential moisture 
changes from the edges of the rolls, which cause various film distor- 
tions such as flute and buckle. 12 

The Shrinkage Characteristics of Various Eastman Motion Pic- 
ture Films. In Table 4 are recorded the approximate shrinkage 
characteristics of a variety of Eastman motion picture films includ- 
ing both nitrate and safety base, and negative and positive emul- 
sions. The accelerated aging test employed consists of heating short 
strips of developed film for 7 days at 120 F and 20 per cent RH, and 
is useful for comparing films of different potential shrinkage. This 
aging treatment is very roughly equivalent to about a year under 
normal conditions for strips of film freely suspended in moving air. 
The figures given for aging shrinkage should not be interpreted as 
indicating the actual shrinkage to be expected in practice. Film in 
tight rolls or in containers of any kind will shrank considerably less, 
while under severe storage conditions the shrinkage may be greater. 

All the safety films in Table 4 have a higher humidity expansion 
or contraction than the corresponding nitrate films. This is due to 
the fact that safety base holds more moisture than nitrate base (cf. 
Fig. 3). However, the humidity expansion of these safety base 
films approaches more closely to that of the nitrate film than was the 
case 6 or 7 years ago. The permanent shrinkage of the older safety 
films (Nos. 2, 4, and 8), as indicated by the processing shrinkage and 
accelerated aging tests in Table 4, is considerably higher than that 
of the nitrate films. The newer safety films (Nos. 3, 5, and 9), on 



258 



J. M. CALHOUN 



Vol 43, No. 4 



the other hand, are quite comparable in this respect to the nitrate 
films. 

Shrinkage of Release Prints in the Trade. The actual shrinkage 
of positive motion picture film encountered in the trade is of inter- 
est, because laboratory tests can never duplicate precisely the vari- 
ety of conditions of storage and projection found in practice. 
Shrinkage measurements (deviations from standard pitch) have 
been made in a number of theaters and film libraries in the northeast 




234 
AGE - TEARS 

FIG. 18. The rate of shrinkage of Eastman Motion 
Picture Release Positives under average trade conditions 
in the northeast United States. Film manufactured be- 
tween 1937 and 1943 (Nitrate, Type No. 6, Table 4; 
Safety 16-mm, Type No. 8, Table 4). Number of pro- 
jections unknown and measurements made at unknown 
equilibrium relative humidity. 

United States. These measurements, of course, could not be made 
at constant relative humidity, so that the values obtained are very 
rough. New prints may be in equilibrium with an atmosphere of 
70 per cent RH, whereas after several bookings the film may be in 
equilibrium with air having a relative humidity of 30 per cent. 
Measurements of this nature, therefore, include permanent shrink- 
age of the raw stock, processing shrinkage, and shrinkage produced 
by subsequent storage and projection, together with an unknown 
degree of reversible humidity expansion or contraction. 

The average deviation from standard pitch for both Eastman 
Nitrate 35-mm and Safety 16-mm commercial prints obtained in the 



Oct., 1944 PROPERTIES AND BEHAVIOR OF FILM 259 

above manner, is plotted against the approximate age of the film in 
Fig. 18. The initial shrinkage on each curve was obtained from 
new prints, which in the case of nitrate is practically zero due to 
the moist condition of the film at the time of measurement. The 
number of projections on the balance of the samples is not known, 
but probably increases with the average age of the different samples 
tested. It may be seen that the nitrate prints released to the trade 
for a year have a shrinkage of about 0.4 per cent. This agrees 
reasonably well with the curve for rolls in untaped cans (Fig. 15), 
determined in the laboratory under controlled conditions. The 
safety 16-mm film released to the trade for a year shows a shrinkage 
of about 0.8 per cent. However, this safety positive film is the older, 
higher-shrink type (No. 8, Table 4) and the present film (No. 9, 
Table 4) will shrink much less under the same conditions. 

The shrinkage encountered in the trade in individual cases may 
vary considerably from that shown in Fig. 18, depending on the 
actual projection and storage conditions in different parts of the 
country. Nevertheless, it is apparent that the deviation from 
standard pitch of present-day motion picture films is much less than 
that for which the projector sprockets were originally designed. 

FILM CURL 

The tendency of a photographic film to curl is well known. Curl 
is usually most pronounced at low relative humidities owing to the 
contraction of the gelatin emulsion. For convenience we have 
called the curl positive when the film is bent toward the emulsion side, 
and negative when the film is bent away from the emulsion side. In 
the case of motion picture film a slight positive curl is generally pre- 
ferred. This is believed to reduce scratching of the emulsion in 
handling. The curl of the film should not be too high at any relative 
humidity likely to be encountered in practice and should not change 
too much with age. Film with excessive curl is difficult to handle, is 
more susceptible to the distortion called "spokiness," 12 and may not 
focus sharply when projected. On the other hand, film which is flat 
is sometimes regarded as too limp, although this may not be a 
serious objection. 

The cause of curl and the effect of relative humidity on curl are 
illustrated in Table 5. It may be seen that when the relative hu- 
midity is reduced from 70 per cent to 20 per cent, stripped emulsion 
contracts approximately 7 times as much as uncoated nitrate base. 



260 J. M. CALHOUN Vol 43, No. 4 

In normal film the emulsion is firmly attached to the base so that it 
cannot contract as much as it would otherwise. Therefore, when 
the moisture content of film is reduced the film bends or curls toward 
the emulsion side to reduce the strain. In addition, the base is 
compressed slightly (cf. Table 5) and the emulsion stretched (com- 
pared with the dimensions it would assume if unattached). An 
analogy is sometimes drawn between this behavior and that of a 
bimetallic strip which consists of 2 elements, each having a different 
thermal coefficient of linear expansion. 

The curl measurements in Table 5 give the average altitude of the 
arc (that is, the maximum distance between the arc and the chord) 
formed by 35-mm film in the widthwise direction. If the film base itself 
were perfectly flat, the emulsion coated film would be nearly flat 



TABLE 5 

The Effect of Relative Humidity on the Curl of Fresh Undeveloped Eastman Nitrate 
Motion Picture Fine-Grain Positive Film 

Widthwise Humidity Contraction from 70 per cent RH, 
per cent 



Relative 
Humidity, 
per cent 


Stripped 
Emulsion 


Uncoated 
Base 


Normal 
Film 


Curl of 
35-mm Film, 
in. 


70 











-0.03 


50 


0.8 


0.10 


0.15 


+0.05 


20 


1.8 


0.25 


0.35 


+0.20 



at high relative humidities and become more positive in curl as the 
moisture content is reduced. However, in most motion picture films 
the base is treated so that it will have a small negative curl to counter- 
act the pull of the emulsion. The film, therefore, has a slight 
negative curl at 70 per cent RH, a small positive curl at 50 per cent 
RH, and a curl at 20 per cent RH which is not as large as it would be 
if the base itself were flat. It is desirable that the curl amplitude, 
that is, the difference between the curl at low and at high relative 
humidities, be as small as possible. 

Curl in Processing. When film is immersed in the processing 
solutions, both the base and emulsion swell. The curl generally 
disappears and the film is essentially flat as it enters the drying 
cabinet. Here the back of the film base begins to dry while the 
face is kept moist by contact with the wet emulsion. This causes the 
film to curl in a negative direction. As the emulsion dries, it con- 
tracts more than the base and finally pulls the latter until the curl 



Oct., 1944 PROPERTIES AND BEHAVIOR OF FILM 261 

changes from negative to positive. This change in the direction of 
curl does not occur gradually as a rule. The film base appears to 
resist the pull of the emulsion as long as possible and may even 
buckle slightly. Finally, the contraction of the emulsion becomes 
sufficiently great, and the curl of the film changes suddenly from 
negative to positive, often within the length of a single strand in the 
drying cabinet. 
As mentioned in an earlier section, the emulsion dries more rapidly 

TABLE 6 

The Effect of Storage Conditions on the Curl of Processed Eastman Nitrate Motion 

Picture Fine-Grain Positive Film 

(Original curl, +0.03 in.} 

Storage 

Relative Curl in Inches After 2 Months' Storage 

Humidity, (Storage Temperature, degrees F) 

per cent 55 70 90 110 

Film Wound Emulsion-In 

20 +0.02 +0.01 -0.03 -0.05 

35 +0.03 +0.04 +0.01 -0.05 

50 +0.02 +0.04 +0.02 -0.02 

65 +0.02 +0.04 +0.04 +0.01 

80 +0.05 +0.06 +0.06 +0.03 

Film Wound Emulsion-Out 

20 -0.04 -0.07 -0.11 -0.13 

35 +0.01 -0.03 -0.08 -0.15 

50 0.00 -0.02 -0.06 -0.11 

65 0.00 -0.01 -0.04 -0.09 

80 +0.01 0.00 -0.04 -0.06 

NOTE: Film conditioned to storage relative humidity before winding and re- 
conditioned to 50 per cent RH at 70 F for measurement. 

than the base, because moisture diffuses more easily from the in- 
terior to the surface in the case of the former. In many commercial 
machines the base is still somewhat moist at the end of the drying 
cabinet, and since it is softer and weaker in this condition, it offers 
less resistance to the pull of the emulsion. Consequently, the curl 
of the film at the point of reeling may be higher than normal for the 
relative humidity of the drying air. Drying at high temperatures and 
low relative humidities should be avoided to prevent excessive curl 
in the drying cabinet. 

The Effect of Storage Conditions on Curl. The curl characteris- 



262 J. M. CALHOUN Vol 43, No. 4 

tics of film tend to change on storage even where the moisture con- 
tent of the film remains the same. Table 6 illustrates the effect of 
several storage variables on the curl level (at 50 per cent RH) of 
developed Eastman Nitrate Motion Picture Fine-Grain Positive 
film over a period of 2 months. It will be observed that the curl of 
the film becomes more positive under some conditions and more 
negative under others. The film wound emulsion-in behaves dif- 
ferently from the film wound emulsion-out. The changes in curl 
are greater at high storage temperatures and low storage relative 
humidities. 

It may help to clarify some of the peculiarities in film behavior if 
we attempt an explanation of the curl changes which occur during 
storage. The following are believed to be the more important factors 
responsible for the effects observed in Table 6 : 

(1) Shrinkage of the base. Shrinkage of the base in the widthwise direction 
tends to counteract the pull of the emulsion and, therefore, makes the curl less 
positive or more negative. The influence of storage conditions on the shrinkage 
of film has already been described in detail. An increase in either storage relative 
humidity or storage temperature increases shrinkage of the base and, we believe, 
accelerates curl changes due to this cause. 

(2} Plastic flow of the base and emulsion during storage in roll form (a) Trans- 
verse flattening of the film. The effects of plastic flow on curl are rather complex. 
If a strip of film having moderate curl is held flat under a weight, one of the 2 
elements (emulsion and base) will be stretched and the other compressed. Since 
neither the base nor emulsion is perfectly elastic, a plastic flow takes place which 
reduces the strain. This tends to make the film flatter regardless of whether the 
curl was previously negative or positive in direction. 

Motion picture film wound in tight rolls is somewhat analogous to the strip of 
film under a weight, since the tension in the roll prevents the film from curling 
in the widthwise direction. The magnitude of this effect is directly related to the 
degree of curl at the time of winding which determines the widthwise stress ap- 
plied in the roll and, therefore, the amount of permanent set. In other words, the 
more curly the film at the time of winding, the greater will be the change in curl. 

Curl changes caused by transverse flattening of the film are increased by heat 
during storage because plastic flow is greater at higher temperatures. Relative 
humidity (or rather the equilibrium moisture content of the film at the time of 
winding) has the opposite effect to that expected. Although film undergoes greater 
cold flow at high relative humidities under a given load (cf. Fig. 12), the curl at 
the time of winding is usually highest at low relative humidities. Since this latter 
factor determines the magnitude of the stress applied in the roll, curl changes due 
to this cause are greatest when the film is wound when in equilibrium with air at 
. low relative humidities. 

(6) Longitudinal winding of the film. The film in roll form is flat only in cross 
section and is wound or curled in the lengthwise direction. This has a compli- 



Oct., 1944 PROPERTIES AND BEHAVIOR OF FILM 263 

cated effect on the subsequent widthwise curl of the film when unwound, which 
we will attempt to analyze. It is common practice to wind raw stock emulsion- 
in and processed film emulsion-out. When film is rolled emulsion-in, the emulsion 
is compressed and the base stretched in the lengthwise direction. Plastic flow 
takes place to relieve the stress and, under suitable conditions, the film takes a 
certain degree of permanent set. Then, when the film is unrolled the emulsion is 
stretched lengthwise and the base compressed. This compresses the emulsion and 
stretches the base in the widthwise direction which tends to make the widthwise 
curl more positive. 

When film is rolled emulsion-out, the effect is the opposite to that described 
above. Unwinding film having a permanent set stretches the base and compresses 
the emulsion in the lengthwise direction. This compresses the base and stretches 
the emulsion widthwise, which tends to make the widthwise curl more negative.* 

The smaller the diameter of the roll the greater is the deformation of the film 
and, therefore, the greater will be the change in curl from this cause. (We have 
found somewhat larger curl changes at the core end than at the outside end of 
1000-ft rolls.) An increase in either relative humidity or temperature increases 
curl changes of this type because of the increased plastic flow and permanent set. 

The above discussion illustrates a few of the complexities in the 
behavior of motion picture film. In addition to the factors described, 
there are undoubtedly others, even more obscure, which influence 
curl. The curl of the film at any given time will be determined by 
all these effects, some of which act in opposite directions, and each 
of which may be influenced in a different way by heat, moisture, and 
other factors. For these reasons it is not always possible to predict 
what the curl of motion picture film will be at any given point in its 
history. 

In the data in Table 6, the effects of shrinkage on curl are difficult 
to distinguish from the effects of plastic flow. However, in the case 
of film wound emulsion-in, plastic flow produced by transverse flatten- 
ing would tend to give a zero curl, while plastic flow produced by 
longitudinal winding would tend to give a more positive curl. The 
fact that the curl actually becomes increasingly negative at low 
relative humidities as the temperature increases, must be attributed 
to shrinkage of the base. At higher relative humidities the effects of 
shrinkage are masked by other factors. 

* It is assumed that at least several feet of film are involved, so that the weight 
of the film itself when unrolled and stretched out will prevent lengthwise curl. If 
a strip of film only a few inches in length is taken from a roll, it will frequently 
curl lengthwise rather than widthwise, particularly if previously wound to a small 
diameter. This behavior is sometimes referred to as "clockspring" from the ob- 
vious analogy. 



264 J. M. CALHOUN Vol 43, No. 4 

The greater change in curl observed in Table 6 at the lower relative 
humidities is believed to be due to plastic flow produced by transverse 
flattening of the film. At the low relative humidities the film has a 
higher curl at the time of winding which increases the widthwise stress 
on the film. The rather surprising fact that the film wound emul- 
sion-in at the higher relative humidities actually becomes more 
positive in curl can be explained by plastic flow produced by the 
longitudinal winding. It may be noted that the effects of shrinkage 
of the base and plastic flow due to longitudinal winding operate in 
opposite directions when the film is wound emulsion-in, but in the 
same direction when the film is wound emulsion-out. This ex- 
plains the much larger negative drift in curl when film is wound 
emulsion-out. 

From a practical point of view Table 6 demonstrates that where it 
is desired to retain a small positive curl, film should be wound emul- 
sion-in at moderate relative humidities (preferably 40 per cent to 
60 per cent); and stored at low temperatures (50 F to 60 F) in taped 
cans. These conditions are more easily fulfilled in the case of raw 
stock. Processed film which is normally wound emulsion-out is in a 
somewhat less favorable condition from the point of view of curl 
changes, although these are generally not serious except where the 
film is reeled when very dry and then stored at high temperatures. A 
film having too high a positive curl may be improved by winding 
emulsion-out, while film having too negative a curl may be im- 
proved by winding emulsion-in. 

CONCLUSION 

The proper performance of motion picture film in practice depends 
to a marked degree on the physical properties of the film, and on how 
these properties are affected by relative humidity, temperature, and 
other factors. The importance of proper protection of film against 
moisture changes during storage, and the exercise of a certain amount 
of control over relative humidity in most operations in the motion 
picture laboratory cannot be overemphasized. 

Safety base motion picture film is now substantially improved in 
its physical properties compared with that manufactured 6 or 7 
years ago, although it is still inferior to nitrate film in some respects. 

It is our hope that this discussion of the physical properties of 
motion picture film will clarify some of the peculiarities in film be- 
havior, and prove of practical value to the motion picture industry. 



Oct., 1944 PROPERTIES AND BEHAVIOR OF FILM 265 

Acknowledgment. The experimental work and the theories de- 
scribed in this paper have resulted from the accumulated efforts 
of numerous members of the Department of Manufacturing Ex- 
periments and the Research Laboratories of the Eastman Kodak 
Company over a period of many years. The writer wishes to express 
his sincere appreciation to Dr. E. K. Carver for his many helpful 
suggestions and for continued guidance in the preparation of the 
paper. Thanks are also due to those who assisted in the collection 
of data and in the preparation of graphs. 

REFERENCES 

1 TALBOT, R. H.: "Some Relationships Between the Physical Properties and 
the Behavior of Motion Picture Film." (Presented Feb. 23, 1944, at a meeting 
of the Atlantic Coast Section of SMPE in New York. To be published in the /. 
Soc. Mot. Pict. Eng.) 

2 HOUWINK, R.: "Elasticity, Plasticity and Structure of Matter," University 
Press (Cambridge), 1937, p. 234. 

McNALLY, J. G., AND SHEPPARD, S. E.: "Double Refractions in Cellulose 
Acetate and Nitrate Films," /. Phys. Chem., 34 (January, 1930), p. 165. 

4 WYND, C. L. A.: "Method of Making Uniaxial Low Shrinkage Cellulose 
Derivative Sheeting," U. S. Pat. 2,260,501 (October 28, 1941). 

6 LEADERMAN, H.: "Textile Materials and the Time Factor. I Mechanical 
Behavior of Textile Fibers and Plastics," Textile Research, XI, 4 (1941), p. 171. 

6 URQUHART, A. R., AND WILLIAMS, A. M.: "The Moisture Relations of Cot- 
ton. The Effect of Temperature on the Absorption of Water by Soda-boiled 
Cotton," /. Textile Inst., 15 (1924), p. T559. 

7 ULM, R. W. K.: "Influence of Atmospheric Humidity and Temperature on 
the Moisture Content of Paper Board," Paper Trade J., 8 (1938), p. 108. 

8 NEWSOME, P. T., AND SHEPPARD, S. E.: "The Sorption of Water Vapor by 
Cellulose and Its Derivatives, Part III. The Heat of Adsorption of Water Vapor 
by Cellulose Acetates," /. Phys. Chem., 36 (1932), p. 930. 

9 SHEPPARD, S. E., HOUCK, R. C., AND DITTMAR, C.: "The Structure of Gela- 
tin Sols and Gels, VI The Adsorption of Water Vapor and the Electrical Conduc- 
tivity," /. Phys. Chem., 44, 2 (February, 1940), p. 185. 

10 WEIGERINK, J. G.: "Moisture Relations of Textile Fibers at Elevated Tem- 
peratures," R.P. 1304, /. Res. Nat. Bur. of Standards, 24 (June, 1940), p. 645. 

11 PERRY, J. H.: "Chemical Engineers Handbook," McGraw-Hill (New York), 
1941, p. 1482. 

12 CARVER, E. K., TALBOT, R. H., AND LOOMIS, H. A.: "Film Distortions and 
Their Effect Upon Projection Quality," /. Soc. Mot. Pict. Eng., XLI (July, 1943), 
p. 88. 

18 OFFENHAUSER, W. H., JR.: "The 16-Mm Commercial Film Laboratory," 
J. Soc. Mot. Pict. Eng., XLI (August, 1943), p. 177. 

14 CARVER, E. K., TALBOT, R. H., AND LOOMIS, H. A.: "Effect of High-In- 
tensity Arcs Upon 35-Mm Film Projection," /. Soc. Mot. Pict. Eng., XLI (July, 
1943), p. 69. 



266 J. M. CALHOUN 

is OTT, E. : "Cellulose and Cellulose Derivatives," Interscience Publishers, Inc., 
(New York), 1943, p. 990. 

16 SHEPPARD, S. E., AND CARVER, E. K.: "Plasticity in Relation to Cellulose 
and Cellulose Derivatives," J. Phys. Chem., 29 (October, 1925), p. 1244. 

17 DAVIS, R., AND STOVALL, E. J., JR.: "Dimensional Changes in Aerial Photo- 
graphic Films and Papers," R.P. 1051, /. Res. Nat. Bur. of Standards, 19 (Decem- 
ber, 1937), p. 613. 



AIDS FOR PICTORIALLY ANALYZING 
HIGH-SPEED ACTION* 



E. M. WATSON** 



Summary. Many of the objects that concern us are of use only when they are in 
motion. While we can watch mechanisms that move slowly to determine whether or 
not their actions confirm performance predictions, the unaided eye is useless to observe- 
high-speed mechanisms. 

To find out what is going on some method of visual aid must be employed. While 
this paper does not cover the entire field of activity in high-speed photography, the 
more important methods are classified, equipment is described, and various applica- 
tions are discussed. 

Many of the objects that concern us are of use only when they 
are in motion. While we can watch mechanisms that move slowly 
to determine if their actions confirm performance predictions based 
on blueprints and slide-rule calculations, the unaided eye is useless 
to observe the behavior of mechanisms that move at high speed. 

Rapid motions cannot be adequately analyzed by the unaided eye 
for several reasons. Because of persistence of vision, images are 
retained by the eye for a short period of time and any motion of the 
image during the period of retentivity will cause the image to appear 
indistinct. Even though there may be momentary periods of repose, 
as a high-speed crosshead at the end of its travel, or when by external 
means it is made to appear motionless, it may not be possible to de- 
termine by these glimpses what is taking place because the rate at 
which the brain can comprehend the performance is exceeded. 

To find out what is going on, some method of visual aid must be 
employed. Just what is practicable to use depends upon many 
different conditions. Of all the different methods available, it is 
necessary to choose the one which will reveal the conditions for which 
a question has been raised. This method must be one for which the 
necessary apparatus can be practically constructed or obtained. If 



* Presented Oct. 29, 1943, at the Technical Conference in New York. 
** Cleveland, Ohio. 

267 



268 E. M. WATSON Vol 43, No. 4 

the phenomenon to be considered is repetitive, some device for direct 
visual observation can be considered, but if not, it is necessary to 
store the records of events photographically or otherwise until such 
time as they can be developed and studied. 

In making estimates as to how a mechanism will perform, it is not 
always possible to forecast all of the effects of motion and, therefore, 
until the mechanism is tried, there is no way of telling how it will per- 
form. In some instances it will be found that the best way to go 
about perfecting a machine is to build a model. When this model is 
put into operation it will likely be found that at low speeds the per- 
formance corresponds to that desired, but as the operating speed is 
increased effects of inertia, slipping, and other conditions many intro- 
duce deviations from performance at low speeds. 

Since it is usually desired to have the machine operate at the high- 
est practical speed in order to get adequate output to justify condi- 
tions, as investment, etc., some method must be employed that will 
assure acceptable operation at the desired speeds. Many times when 
using the trial and error method a number of changes will have to be 
made. Further operation and subsequent examination will prob- 
ably determine the extent of the improvement and offer a clue as to 
what to do next. 

When progress is difficult or impossible by this procedure, seeing 
what happens while the erroneous action is taking place will often 
show what to do to obtain the desired performance. 

Choices of apparatus necessarily depend on what is to be accom- 
plished. Versatility of application is of considerable importance 
when the apparatus represents considerable outlay. A knowledge of 
methods of examination of phenomenon too fast for unaided visual 
observation is essential in making a proper choice of equipment. 

In general, the available methods are of value only where there 
is an appreciable movement to be shown. Dimensions of a few mils 
can be shown under special conditions. Variations of hundredths 
and tenths of inches are within the normal range of equipment of this 
kind; but the field area should be so selected that the motions looked 
for exceed one per cent of the diameter of the field area. 

On account of these limitations it is best to try to study only one 
condition at a time, but it is well to make some general views to locate 
the areas where the detail can best be studied. 

Colored photographs at high speed will often show some things 
which cannot be adequately studied with the use of black-and-white 



Oct., 1944 AIDS FOR ANALYZING HIGH-SPEED ACTION 



269 






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.270 E. M. WATSON Vol 43, No. 4 

films. For example, colors of flames in gas can give added insight 
to what is taking place. Solid or liquid materials such as those used 
in silver soldering may be identified readily by color, whereas their 
identification will be difficult or impossible by the use of black-and- 
white film. Various ferrous and nonferrous metals can be made to 
show distinctive photographic color and shade. 

Often accessories to the available devices are required. Much of 
the success in getting data difficult to obtain will be found propor- 
tional to the extent to which accessories can be constructed. 




FIG. 1. Ashdown Rotoscope for making observations under 
conditions where light from subject being observed prevents 
the use of ordinary stroboscopic methods. 

The classification of means for pictorially analyzing motions that 
are too rapid for unaided visual observation is included as Table 1. 
The column at the left lists various general types and arrangements of 
apparatus; the middle column outlines the manner in which investi- 
gations are made when the subject is continuously lighted; and the 
column at the right applies to methods employing intermittent light 
on the subject. 

In almost every setup the following points must be considered: 

(2) Means must be devised for placing the image (with necessary sharpness 
.and steadiness) on the medium where the exposure is to take place. 

(2) Arrangements must be made for starting and stopping the exposure. 



Oct., 1944 AIDS FOR ANALYZING HIGH-SPEED ACTION 



271 



(5) Means must be devised for placing the subsequent exposures on recording 
material at the proper time and location to obtain the desired results. 

Recognition of these requirements gives some idea of the method 
of accomplishment in each case. 




FIG. 2. Stroboscopic equipment used for demonstration purposes. 
In the normal operating position, the tube and reflector are turned 
toward the wheel. The useful light from the Stroboscopic tubes 
originates either in mercury vapor or rare gases. 



VISUAL OBSERVATION 

Item 1 of Table 1 refers to the visual observation of repetitive phe- 
nomena, such as take place in the action of engines or of other devices 
where a specific motion is continually repeated. 

When continuous light of sufficient intensity is reflected from or 
radiated by the subject that is to be observed, some type of shutter 
must be employed to pass light from the subject to the observer only 
at times when similar images will be seen. 



272 



E. M. WATSON 



Vol 43, No. 4 



Such a shutter control of the light that reaches the eye is provided 
in the Ashdown Rotoscope (London), shown in Fig. 1. The ob- 
servations are made through 2 slots in a tube which is revolved on its 
axis by a spring motor. These slots are fitted with vanes which fur- 
ther restrict the passage of light to only a very short interval out of 
each half revolution. By means of an adjusting knob, the observer 
can control the speed of the rotating tube and hence can view the 
performance of the subject at any one point in its operating cycle 
(by adjusting the rotoscope to synchronism with the subject) or 




FIG. 3. 



Camera and lights with synchronizing equipment for obtain- 
ing single exposures at high shutter speeds. 



throughout its cycle (by adjusting the rotoscope to a slightly different 
speed). Included also are speed-change gears which provide for a 
choice of any one of 4 basic speeds and thus give the device a consid- 
erable speed range of application. 

Under conditions where existing continuous light reflected or radi- 
ated from the subject is not so bright as to overcome the contrasts 
introduced by an addition of intermittent light, the stroboscopic 
method of examination can be used to advantage. 

Fig. 2 shows the stroboscope that was used in the House of Magic 
demonstrations at the New York World's Fair. The tube mounted 
in the reflector is filled with neon. The power to operate the tube is 
taken from a condenser which quickly discharges during each flash > 



Oct., 1944 AIDS FOR ANALYZING HIGH-SPEED ACTION 273 

causing the light to be of very short duration. The necessary circuit 
is provided for recharging the condenser at sufficient speed to allow 
the flashes to take place at the rate of once for each revolution of the 
wheel, which is driven by a synchronous motor. The circuits used 
depend on how the equipment is to be employed. 

When a particular point of an operating cycle is being studied, the 
flashes of light should be made to coincide with that point of the 
operating cycle, though the timing of the light may also be varied 
somewhat to bring other points of the cycle into view. Apparatus 




FIG. 4. An example of high-speed photography accomplished 
with the type of equipment illustrated in Fig. 3. 

for this work can sometimes be constructed from equipment that is 
at hand, but in most cases it is more economical to purchase apparatus 
designed for the purpose. 

STILL CAMERAS 

Whenever the subject being investigated does not repeat its mo- 
tion at all or not often enough to use a stroboscopic device, it is neces- 
sary to use some form of photography for quickly recording the action 
for later study. When complications are not great, still cameras can 
be used. 

Single Images. When it is not necessary to know what happens 
before and after a given instant, a single exposure on a stationary 



274 E. M. WATSON Vol 43, No. 4 

film may suffice. In Table 1, this condition is listed as 2 (a). For 
many applications much can be accomplished with still cameras, par- 
ticularly if the camera's shutter is capable of a speed of the order of 
Yiooo of a sec. 

Fig. 3 shows a setup used by Jack Price in taking single shots at 
very high shutter speeds. Attached to the camera is a synchronizer 




FIG. 5. Photograph of a 0.30-caliber bullet (ve- 
locity 2700 ft per sec) striking an electric lamp bulb. 
Note that the cracks in the glass travel faster than 
the bullet. An exposure of less than 2 X 10" 6 sec 
is required to "stop" the bullet without blur as 
shown in this picture. 

which makes possible the electrical signal that the opening in the 
curtain shutter is approaching the film. This signal is in advance 
of the uncovering of the film by an amount which will allow the Photo- 
flash lamps to reach the desired plateau of light intensity by the time 
the exposure is started. The synchronizer reduces the voltage on the 
grid of a thyratron tube to a point where the tube is made conducting, 
thus causing the lamps to be set off. The lamps in each cluster are 
connected in series. The leads from the clusters are plugged into the 



Oct., 1944 AIDS FOR ANALYZING HIGH-SPEED ACTION 



275 



box containing the thyratron tube, etc., and the usual arrangement is 
to have them in parallel. Fig. 4 shows a picture of two dancers taken 
by this method. 

Single-shot exposures may also be taken by stroboscopic light, ex- 
amples of which are shown in Figs. 5 and 6. These stroboscopic pic- 




FIG. 6. A microsecond silhouette photograph taken with strobo- 
scopic polarized light to show the stress pattern during the growth of 
the cracks in a glass plate when violently broken. The crack ve- 
locity is 5000 ft per sec. It is measured by taking 2 photographs 
spaced in time by 15 microseconds. 



tures, and those in Figs. 9 and 13, were obtained from Dr. Harold 
E. Edgerton, K. J. Germeshausen and H. E. Grier, who have 
very ably used the technique of flash photography at the Massa- 
chusetts Institute of Technology. The apparatus and methods have 
been widely described. 1 

Even with a still film or plate and no camera, instructive silhouette 
photographs can often be taken by interposing the moving object be- 



276 



E. M. WATSON 



Vol 43, No. 4 



tween the stroboscopic light source and the sensitized material. For 
example, in the study of the flight of projectiles fired from a gun, the 
compression and rarefaction of the air due to the sound wave will re- 
fract the light, causing it to show in a photograph. Fig. 7 shows a 
0.50-caliber projectile traveling about 2400 ft per sec, as photo- 
graphed by Dr. A. C. Charters of The Aberdeen Proving Ground 
(Md.). The sound wave from the bow and stern may be seen, as 
well as the wave from the grooves caused by the rifling. The turbu- 
lence of the air in the path just traversed by the projectile can also be 
seen. 

Multiple Images. When the action to be studied moves across 
the field of view, multiple exposures on a single plate can be used 




FIG. 7. A single-flash silhouette picture of a 0.50-caliber projectile in flight. 

to record what takes place. In Table 1 this condition is listed as 
2(b). The photograph in Fig. 8, taken by Otto Schurig, of an arc in 
a contactor, 2 is an example of an action recorded by multiple-image 
photography. A disk with a series of radial slots near its periphery 
was revolved before the still camera lens during the time the arc took 
place. The various positions of the arc were recorded when the 
slots in the disk successively uncovered the Jens. The difference in 
brightness of the various images of the arc is caused by their being 
taken at various points on the a-c cycle. 

The stroboscopic images of the golf club in Fig. 9 show its relative 
speed before and after striking the ball and also the distortion of the 
staff as a result of the impact. The ball is compressed when struck, 
some of the kinetic energy supplied by the club being taken up as po- 
tential energy by the rubber of the ball. As the ball decompresses, 



Oct., 1944 AIDS FOR ANALYZING HIGH-SPEED ACTION 277 

much of this potential energy goes into the kinetic energy of motion 
of the ball. It is the addition of this energy to that of the push of the 
club which accounts for the ball's flight at a speed higher than that 
of the club by which it was struck. The flash frequency was 600 per 
sec, which allows the speed of the club and ball to be calculated on 
the basis of the distance between individual images. 




FIG. 8. High-speed multiple-exposure photograph of 
arc interruption, showing successive stages of the arc at 
intervals of about Vsoo of a sec. 

MOTION PICTURE CAMERAS 

When a single picture is insufficient and the motion occupies ap- 
proximately the same area, causing multiple images to overlap and 
to be confused, one must resort to motion pictures. Motion pictures 
taken at speeds in excess of the regular projection speed will, when 
projected, show the action in slow motion. In Table 1 motion pic- 
tures are listed as 3. 

Intermittent Film Movement. If the difference between taking 
speed and projecting speed need not be very great, an intermittent 
camera 3 (a) would be suitable. In this type of camera the film is 



278 



E. M. WATSON 



Vol 43, No. 4 



drawn from the supply reel and wound on the take-up reel at constant 
speed. However, film is stationary adjacent to the aperture when 
each exposure is made. It is advanced intermittently past the 
aperture for the exposure of each successive frame, and the light 
through the optical system is interrupted during the motion of the 
film. Fig. 10 shows a Bell and Howell super-speed 16-mm camera 




Photo Courtesy A. G. Spalding & Bros. 

FIG. 9. Multiple-image study of impact and reactions of 
golf club and ball. 

which will operate at about 128 frames per sec or 8 times the normal 
projecting speed. Most of the slow-motion pictures of athletic 
events, etc., shown in theaters are taken at about this number of 
frames per sec. 

The Eastman Cine-Kodak Special fitted with a stroboscope has 
been used to study the operation of looms, etc., by the Bigelow San- 
ford Carpet Company, Inc., as shown in Fig. 11. A commutator is 
attached to the shaft on the camera which would otherwise accommo- 



Oct., 1944 



AIDS FOR ANALYZING HIGH-SPEED ACTION 



279 



date a crank. This commutator, extending to the right of the camera 
operator, is connected to the stroboscope control apparatus that is in 
the black box. The stroboscope lamp is caused to operate at the 
time the camera shutter has completely uncovered the film. 

Continuous Film Movement. When it is desired to operate at 
a picture frequency in excess of that attained with an intermittent 




FIG. 10. Bell and Howell super-speed camera in which the 
film moves intermittently. This camera is sometimes called 
the golf -stroke-analysis camera. 

camera, a camera in which the film moves continuously without 
stopping must be employed. In the class of cameras designated as 
3(b) in Table 1, the film is passed from one spool to another at a con- 
stant speed, once the desired speed has been attained. The images 
are either placed on the film almost instantaneously by means of 
stroboscopic light or allowed to travel with the film for a short dis- 
tance by means of an optical system. 

The stroboscopic camera of this type is very simple in construction, 
because its optical system consists of only an ordinary lens which is 



280 



E. M. WATSON 



Vol 43, No. 4 



arranged to focus the image on the film as it passes. The strobo- 
scopic exposures are usually so short that the motion of the image on 
the film is less than the dimensions of the optical errors of the lens 
(circles of confusion), and therefore the motion of the image is not 
noticed. This method has the advantage of stopping very fast mo- 
tion which would blur the image on the film if continuous light and a 
camera which allowed a longer period -of exposure were used. An- 




FIG. 11. Eastman Cine-Kodak Special fitted with a stroboscope 
and set up to make a high-speed record of an action in the operation of 
a loom. 



other advantage of this type of camera is that the light is on the sub- 
ject only while a picture is being taken and, therefore, has less heating 
effect than if it were left on continuously. 

Cameras that employ an optical system to move the image with 
the film can be used to advantage in photographing subjects which 
radiate continuous illumination. Various methods have been used 
in constructing cameras of this type. The Jenkens camera displayed 
in the Smithsonian Institution at Washington (D. C.) employs a ring 
of lenses which move with the film. The Eastman high-speed cam- 



Oct., 1944 AIDS FOR ANALYZING HIGH-SPEED ACTION 



281 



eras employ a revolving glass plate which moves the image along with 
the film. The same effect is accomplished in the Zeiss camera by 
means of mirrors. The top speed of all these cameras which use 
spooled film is limited by the rate at which the camera can pass film 
from one spool to another without serious damage to the film. 

At the present time, the practical upper limit of film speed seems 
to be about 100 miles per hr. Using full frames of 16-mm film, this 




FIG. 12. Eastman Type II High-Speed Camera and accessories set 
up for recording the performance of a contact mechanism. 

speed would correspond to a picture frequency of 6000 to 7000 frames 
per sec. When several pictures are placed in the area regularly oc- 
cupied by one picture, it is possible to increase further the picture 
frequency. This usually cannot be done, without major alterations, 
in a camera having an optical system that moves the image with the 
film, but it is not difficult to accomplish in a stroboscopic camera. 
To make the change in the latter camera, about all that is necessary 
is a mask to limit the field on the film and a means of producing the 
stroboscopic flashes at the desired increased frequency. Pictures 



282 



E. M. WATSON 



Vol 43, No. 4 



taken under these conditions and intended to be projected as motion 
pictures should be rephotographed with an animation camera, en- 
larging to full-frame size the section 
of the film on which the desired ac- 
tion took place. 

Fig. 12 shows a view of the East- 
man Type II High-Speed Camera, 
which uses 16-mm film, set up for 
operation. Projection-type incan- 
descent lamps in reflectors are 
placed at each side of the camera 
to illuminate the subject being 
photographed. In the box on the 
floor in the left background is a 
200-cycle tuning-fork frequency 
generator which provides energy for 
operating a clock. This clock is lo- 
cated in the lower part of the cam- 
era. Its image is photographed at 
the right-hand edge of each frame 
and enables the time to be read to 
lOOOthsofasec. 

Fig. 13 shows an enlargement 
from a strip of film taken at ap- 
proximately 600 frames per sec with 
a stroboscopic camera. The se- 
quence shows the action of an 
automatic 0.22-caliber pistol. This 
is a subject which can be taken 
with either the special-shutter type 
or ^stroboscopic type of camera 
that utilizes continuously moving 
film, a fact that is true in most 
instances of practical high-speed 
photography. 

Mechanically Supported Rotat- 
ing Film. When there is required 
a picture frequency greater than that which can be obtained with 
the types of cameras in which the film is passed from one spool to 
another, it is necessary to mount the film on a drum for support. 




FIG. 13. Motion picture of the 
action of a .22-caliber automatic 
pistol. This is a sequence from a 
high-speed 35-mm film taken at ap- 
proximately 500 frames per sec. 



Oct., 1944 AIDS FOR ANALYZING HIGH-SPEED ACTION 



283 



This arrangement is listed as 3(c) in Table 1. The greatest speed so 
far known is that attained by D. C. Prince and W. K. Rankin who 
constructed a camera that will take 1000 pictures at rates up to 120,- 
000 pictures per sec. 3 A front view of this camera is shown in Fig. 14 
and the rotor in Fig. 15. The film used is 4 ! /2 in. wide by 40 in. long 
and contains space for 10 rows of images, each row consisting of 100 
individual pictures. At maximum rotational speed, the length of 
the film is sufficient to record an event lasting Vi2o of a sec, which is 
equal to one alternation of 60-cycle alternating current. 




FIG. 14. Front view of high-speed pinhole camera 
that can take pictures at the rate of 120,000 per sec. 



Cameras of this type are limited to the photography of phenomena 
which are complete in one revolution of the rotor, unless special pre- 
cautions are taken to prevent interference from multiple exposures 
on the film, or unless a high-speed shutter is used to block out the 
light except during the one revolution. Because of the very short 
exposure the subjects should be of very great brightness. Either 
black-and-white or color film can be used. 

This camera was built to study the performance of high-speed 
switchgear, and when operated at the highest speed it is especially 
valuable in photographing arcs which are extinguished after one al- 



284 



E. M. WATSON 



Vol 43, No. 4 



tarnation . The film is held, by centrifugal force, on the inside of the 
rim of the rotor, with the emulsion away from the main shaft. The 
rotor is so constructed that it consists essentially of 1000 very small 
cameras having pinhole lenses. These pinholes correspond to the 
first zones of zone plates, and are of such size as to give the best image 
under the conditions in which they are used. The images are ex- 
posed progressively from one row to the next, until the tenth row is 
reached. This is followed by repetitions, beginning each time with 




FIG. 15. Rotor with pinhole lenses which supports 
the film in the camera shown in Fig. 14. 



the first row. The pictures may be printed on paper for examination 
in the same manner as is done in still photography. If it is desired 
to show them as a motion picture, it is necessary to photograph in- 
dividual views with an animation camera in order to locate each pic- 
ture properly in the desired frame area. 

Mechanically Supported Stationary Film. Instead of causing 
the film to rotate, it may be placed in a stationary drum and the 
light caused to sweep over it if the objects to be photographed give 
off light sufficiently stroboscopic to permit intelligible images to be 
obtained. Such devices have been used by Dr. K. B. McEachron, 



Oct., 1944 AIDS FOR ANALYZING HIGH-SPEED ACTION 285 

J. H. Hagenguth, and C. J. Kettler for studying lightning dis- 
charges. 4 - 5> 6 

In addition to facilitating the study of the formation and history of 
lightning strokes, cameras of this Boys type may be used to study the 
phenomena associated with the start of sparks and arcs and also the 
entire history of a spark or arc. Two such designs of cameras have 
been built, known as the low-speed and high-speed types. A record 
made with the high-speed camera is shown in Fig. 16. Fig. 17 shows 
the end of the camera in which the film cylinder is located. The 
housings for the 2 objective lenses and the 2 prisms may also be 
seen. The rotation of these causes the light to sweep along the film. 





Time - -U Time -+Time Time 

Current peak al end of !$1 dtschg 2nd dischg - leader vel 71 ft/u sec 

No leader 

FIG. 16. High-speed Boys camera photographs of multiple-stroke lightning 
to the Empire State Building tower. 

This type of camera will give a continuous record of the propaga- 
tion of a spark during its formation and the change in intensity after 
it is formed. The maximum power of resolution so far obtained is 
"/i.ooo.ooo of a sec, or 11 MS per mm of the film. By enlarging the pic- 
tures obtained, shorter times can be investigated. Speeds of propaga- 
tion of lightning strokes as high as 65,000 miles per sec have been 
measured. 

CONCLUSIONS 

In any kind of high-speed photography, all the limitations of or- 
dinary photography are encountered plus some special restrictions 
imposed by the high speed. As types of cameras are changed to ob- 
tain increased speed, compromises in image quality and in exposure 



286 E. M. WATSON Vol 43, No. 4 

must be made. In the operation of an intermittent camera of the 
type mentioned as 3 (a) in Table 1, the film is stationary while the 
exposures are made. This allows the best quality of image to be ob- 
tained from the lenses, a variety of which may be used. Only a 
moderate amount of light is needed, and both black-and-white and 
color film can be used. 




FIG. 17. Interior of the high-speed Boys camera, showing 
the stationary film cylinder and rotating lenses and prisms. 



At high speeds where a camera of the type designated as 3(b) in 
Table 1 is used, in which the film is passed from one spool to another 
without intermittent motion, it is necessary to increase the intensity 
of the illumination because the time of exposure is shortened. It is 
fortunate, however, that, owing to the deviation from the reciprocity 
law, the intensity of illumination does not have to be increased quite 
in proportion to the reduction in exposure time. Focal length and 



Oct., 1944 AIDS FOR ANALYZING HIGH-SPEED ACTION 287 

width of aperture of objective lenses are often limited for cameras 
which require an optical device for moving the image with the film. 

Of the 2 general types of cameras, the stroboscopic type will usually 
give the better quality of image. With it there is no restriction on 
the focal length of the lens or the wideness of the aperture. When 
the camera is run at regular speed, there are only minor variations 
such as vibration, etc. which might cause the film to take a slightly 
different position than was intended. The lighting requires the 
most attention, since it must be of extremely short flashes for which 
special electrical equipment is required. The stroboscopic light thus 
produced is usually quite actinic, which simplifies the film require- 
ments for black-and-white photography. If color photographs are 
to be made, attention must be paid also to having proper color bal- 
ance. 

For cameras in which the images are moved optically with the films, 
the lighting is simple but the lens and other camera requirements are 
more complicated. For most purposes, the light from incandescent 
lamps, the sun, or the subject itself will be adequate. 

Among the opitcal systems of these cameras are some in which the 
motion of the image does not follow the film exactly, and in which the 
optical distance through the system varies slightly during exposure. 
These 2 factors contribute to the conditions that prevent high-speed 
pictures being as good as those obtained with the same lenses when no 
optical system for moving the image is employed. The loss in quality 
in most cases is about the same as that occasioned in changing from 
16-mm film to 8-mm film when running at normal speed. The part 
of the optical system for moving the image limits the use of lenses to 
those of the longer focal lengths, restricts the amount of light that can 
be passed by increasing the lens apertures, and causes some loss of 
light enroute. 

The speed range of high-speed photography is continuous. At one 
extreme there is the example of the telephone companies' photograph- 
ing of call counters. Here the visual observation period can be very 
long but the detail is necessarily great. By these pictures, errors can 
be checked. The other extreme is the camera for studying lightning 
flashes. Here the detail to be observed may not be great but the 
visual observation period is very short. 

There is opportunity in high-speed photography for anyone having 
only modest equipment, but many of the applications require very 
expensive equipment which has little versatility. 



288 E. M. WATSON 

REFERENCES 

1 An extensive bibliography on high-speed photography is included in the re- 
cent book "Flash" by H. E. Edgerton and J. R. Killian, Jr. 

2 JONES, B. W., AND SCHURIG, O. R. : "The Performance of Contactors as Cir- 
cuit Interrupting Devices," General Electric Review, 39 (Feb., 1936), p. 78. 

3 PRINCE, D. C., AND RANKIN, W. K.: "A 120,000-Exposure-Per-Second 
Camera," General Electric Review, 42 (Sept., 1939), p. 391. 

4 MCEACHRON, K. B.: "Lightning to Empire State Building," J. Franklin 
Inst., 227 (Feb., 1939), p. 156. 

6 HAGENGUTH, J. H.: "Lightning Recording Instruments Part II," General 
Electric Review, 43 (June, 1940), p. 248. 

6 KETTLER, C. J.: "Cameras for Lightning Studies," Phototechnique, 2 (May, 
1940), p. 38. 



FAST MOTION ANALYSIS AS AN AID 
TO ORGANIZED INVENTION* 



E. M. WATSON** 

Summary. In getting any device ready for a test it is necessary to consider what 
is to be found out about it, the complete equipment to be used in the test, and the 
preparation needed to put the device into proper condition for conducting the test. 
This paper describes the various ways of recording the performance of fast-moving 
mechanisms, and includes a discussion of how to analyze and apply the data to 
practical development of apparatus. 

During a war fear of the consequences, if it should be lost, causes 
the greatest possible efforts to be put forth in the attempt to win it. 
Just as mechanical devices are used to increase production in peace- 
time, they are likewise employed in times of war to make the efforts 
of the soldiers more effective. Of these mechanical devices, many 
operate too fast for their performance to be observed by the unaided 
eye. In some instances in the development of these devices or in 
their adaptation to new uses, the various aids for analyzing fast mo- 
tion can be utilized to advantage in determining any appreciable 
variation from the desired performance. In the past it was necessary 
to do this work entirely by trial and error, examining as evidence 
after operation scarred, worn, misplaced, deformed or broken parts. 
When conditions permit the use of these analysis aids, usually less 
time is used in discovering the deviation from the wanted operation 
than would otherwise be used. 

The procedure for this accomplishment is shown in Table 1 with 
the following comments conforming to the sequence of items given. 

In getting any device ready for a test it is necessary to consider 
what is to be found out about it, the complete equipment to be used 
in the test, and the preparation (such as cutting windows, etc.) needed 
to put the device into the proper condition for running the test in 
mind. Listed in "Taking of test data" are various devices which 
may be used. 

* Presented May 4, 1943, at the Technical Conference in New York. 
** Cleveland, Ohio. 

289 



290 E. M. WATSON Vol 43, No. 4 

If performance in a single area, showing motion in 2 dimensions, 
and to some extent in a third, as a function of time is desired, pic- 
torial equipment may be used. This includes means for stopping mo- 
tion for visual examination, such as by a stroboscope or by a shutter, 
as well as by photographically recording the image for later leisure 
examination. The advantage of this lies in the fact that there is no 
change in the performance from loading of the parts by the recording 




FIG. 1. Film on which recording is made being placed on camera 
attached to oscillograph. These with the amplifiers, power units, 
etc., mounted on the wall are part of a travel and strain gauge setup. 

instruments. The various devices that may be used for this are de- 
scribed in a previous paper. 1 

If a record of motions in several directions and from different loca- 
tions is desired, an oscillograph and companion equipment may be 
used (Fig. 1). For relatively large motions covering whole or or- 
dinary fractions of inches, the electrical values to be recorded by the 
oscillograph may be produced by the use of equipment employing a 
travel gauge or a slide wire resistance. For smaller motions, in the 
range of thousandths of inches, equipment employing a strain gauge 
or a piezoelectric pickup may be used. These devices may be con- 
structed so as to read very small changes in dimensions, and when 



Oct., 1944 



Taking of 
test data 



Preparation 
of test data 



Examination 
of test data 



Results 



FAST MOTION ANALYSIS 

TABLE 1 



291 




Oscillograph 

and companion 

devices 



Direct 
recording 
on paper 



Assemble into 
motion picture 
reels with titles 
& normal speed 
preface shots 



Make enlarge' 
ments on paper 
for examination 
by individual 
pictures 



Curves of 
performance 

plotted or 
obtained from 
graphic record 



By people 

directly 

concerned 




By others who 
may be able 

to offer 
suggestions 



Success 




Failure 

Method does 
not reveal 
defect. No 
known way of 
correcting 
defect if 
revealed 


Analysis shows 
that desired 
performance 
has been 
obtained 



Special 
devices 




To taking 
of test data 



292 



E. M. WATSON 



Vol 43, No. 4 



mounted on various parts that are to be stressed, they are sufficiently 
sensitive to permit, in most cases, the determination of instantane- 
ous stresses from the record of the resultant strain. Each individual 
application of these gauges must be calibrated on the part used. Also 
in some instances a photoelectric cell may be employed to advantage 
in a pickup. Through the use of the oscillograph, electrical conditions 




FIG. 2. High-speed camera and accessories set up for photographing the 
operation of an ammunition feeder for a 20-mm aircraft cannon. A drum for 
the use of waxed paper may be seen directly behind the lower end of the vise 
handle. 

present in the device under test may also be recorded simultaneously 
with the motion. 

When the motions are in one direction and in a limited area, direct 
recording on paper may be employed. This can be done either with 
a pencil or a pen on ordinary paper, or with a stylus on waxed paper, 
or paper otherwise coated to show the path of the stylus (Fig. 2) . 

Under the heading "Special devices" comes such apparatus as may 
have to be constructed specially to do the particular job in question. 
If there is considerable testing of a certain type to be done, these 



Oct., 1944 FAST MOTION ANALYSIS 293 

special devices may facilitate much saving of time. However, since 
to some extent tests may be conducted with more than one of the 
devices listed, it is preferable, if possible, to use what is at hand rather 
than to construct special devices. 

Under the heading "Preparation of test data" the processing of the 
results varies with the purpose for which these results are to be used. 
Motion picture film which has been examined for performance of the 
subject as soon as ready may be made into reels with normal speed 




Fig. 3. Cardboards to which description and enlarge- 
ments from individual motion picture frames are attached 
and which are joined by tape hinges. The action of lock- 
ing of the 20-mm aircraft cannon may be studied picture 
by picture. 

preface shots and titles for later showing to people who may be in- 
terested in the particular subjects involved. The individual frames 
of the movie may be copied and enlarged on paper (Fig. 3). These 
enlargements, when mounted 5 to a page, with typed description of 
what happened adjacent, may be made into a stack with tape hinges 
so folded that 2 pages at a time may be brought into view or, if a 
longer sequence of action is to be examined, as much as is required 
may be completely unfolded with all the views being in the proper 
relation as in the original motion picture film. 

In some instances it is desirable to plot performance curves showing 
the position of the various parts being studied as a function of time. 



294 E. M. WATSON Vol 43, No. 4 

This may be done either by projecting the film as individual pictures 
on the screen and measuring the positions of parts (Fig. 4), or by 
measuring the silver prints made for the stack as described above. 

By the use of the physics formulas F = MA and E = 1 /z MV Z , it is 
sometimes possible to estimate the energy in the various moving 
parts and the forces incident to the transfer of energy to and from 
them. Sometimes it is found that several unknowns which cannot 
be evaluated are involved. For example, a force may be pushing an 
object which is being impeded by friction. Any acceleration or de- 




FIG. 4. The special projector for examination of motion 
picture film. Horizontal and vertical scales with movable 
transparent rulers permit measurements of positions of the 
subject to be made. 

celeration of the object is the result of the difference between the 
rates at which energy is being added and subtracted. The friction 
involved is often difficult to evaluate, because the coefficients of fric- 
tion and pressures normal to the travel of the object are not easily 
determined. This is particularly true when explosions are involved 
during the operation of apparatus when there are very violent shock 
waves in the materials themselves causing almost incredible condi- 
tions to be revealed. 

With reference to "Examination of test data," the people who are 
only occasionally in a position to make use of these data are often 
only slightly familiar with the methods by which they were obtained. 
To have the data as nearly as possible in the form with which they are 



Oct., 1944 FAST MOTION ANALYSIS 295 

familiar will considerably expedite the progress that can be made in 
this kind of activity. 

When trials are made of a device in the development stage, there 
are usually a number of details involved in the setup which are of in- 
terest only to the men who have asked for the test to be run, and there 
would be little value in any general showing. There is some advan- 
tage, however, in building up a library in which different kinds of de- 
vices are shown. Thus when there is a situation needing attention, 
a record of a similar situation will be available which can be re- 
viewed to form an estimate of what can be accomplished in the cur- 
rent situation. 

Most of the progress in mechanical devices has been by the trial and 
error method and, although these devices may operate very satis- 
factorily, it may not be known just what does take place or how much 
margin there is before unsatisfactory operation will result. It may 
be found that a device in question does work satisfactorily for the 
original purpose, but does not work satisfactorily when it becomes a 
part of a new combination. 

It is when the first construction of a device which a designer has 
originated is complete and is being given its initial trials that these 
methods of analyzing fast motions are of most value. The designer 
has proposed certain operations when the apparatus was laid down on 
the drafting board, but he may not have chosen the best way to attain 
these, since there may not have been sufficient experience on the sub- 
ject to permit the best decision to be made. When the completed 
device is given its initial trials, certain variations from the desired 
performance may be found, at this time there is more improvement 
to be made than there will ever be at any other time, as later some of 
the discrepancies will have been eliminated by whatever means there 
is available. 

Since mechanical development has preceded by considerable time 
the development of methods of fast motion analysis, and so many 
things which have not been analyzed are already in use, there ap- 
pears to be more opportunities for work on existing devices, particu- 
larly with regard to new applications, than for pioneer work at the 
time of origination of new devices. It is most essential that all at- 
tention be given to possible improved designs before decisions on 
specifications for quantity production of a device are arrived at. In- 
formation that is acquired later might have been of use if it had been 
known before the decision for quantity production was made, but 



296 E. M. WATSON Vol 43, No. 4 

once made the benefits to be derived from any improvements may be 
more than offset by the disadvantages involved in trying to incorpo- 
rate them into already finished production. In the war period, when 
time is at a premium, it is necessary to make decisions quickly and 
compromise any possible future improvement with the advantage 
of having what is now on hand available in quantity at an earlier date. 
It is imperative that what is done in the field of fast motion analysis 
be completely accomplished in the minimum time while it can still be 
used. 

As contrasted with the difficulties encountered in current develop- 
ment, there is value to be obtained through the studying by many 
people of regular operation of standard equipment. Since the stand- 
ard equipment may be used as component parts in many different 
assemblies, general knowledge of what happens during its regular 
functioning may facilitate the origination of better methods of em- 
ploying such equipment by those who are to use it as units in their 
designs of larger assemblies. 

There is now a question of how a fast motion analysis activity may 
be fitted into an already existing organization. Much depends on 
finding personnel who may be interested in, and adapted to, doing the 
kind of work needed. It is noted that with the limited experience up 
to the present no conclusive answer can be given, but it is believed that 
in general the purchase of a high-speed motion picture camera for use 
in the photographic department of an establishment is not the best 
way to go about it. Instead of making the fast motion analysis ac- 
tivity an appendix to an existing activity of still and ordinary speed 
motion pictures, the point of view should be more that of a develop- 
ment project, since considerable original thought and pioneer con- 
struction are involved in devising and reducing to practical methods 
the means for best obtaining the different kinds of data needed. 
Reasons for not just simply adding this activity to the work of the 
photographic section are mentioned more fully in the following para- 
graph. 

In order to record extremely fast motions adequately and to inter- 
pret the data therefrom, it may be necessary to construct special 
apparatus and to use complicated processes which are as involved as 
determining the interface distances of crystals from the photographic 
record made on an X-ray diffraction camera, or the weights of mole- 
cules from the photographic record made on a mass spectrograph. 
Photography may not even be necessary for making records of certain 



Oct., 1944 



FAST MOTION ANALYSIS 



297 



kinds of performance, and of course, it does not enter into the inter- 
pretation, which may be found to require a longer time than perform- 
ing the experiment. It appears that the best arrangement for carry- 
ing on such an activity is to have it done by people experienced in de- 
velopmental engineering, so that the evidence, when revealed, will be 
quickly evaluated with regard to the project, and that adjustment of 
subsequent procedure may be made with a view to further develop- 
ment of the technique employed. 

Furthermore, there are other factors to be considered with regard 
to the introduction of a high-speed photographic activity. The ac- 



TotU use Successful 
xi Ti success fu.1. 




FIG. 5. 



tual amount of use expected to be given to the photographic device 
employed in this activity can be gathered from the curves of Fig. 5. 
At first, the novelty of the device and the fact that some applications 
may be long-standing will provoke a high level of use, represented by 
the solid line. Then it will be used many times where useful results 
will not be obtained, represented by the space between the solid and 
dotted lines. Finally, the ultimate use of the camera, after the nov- 
elty has worn off and the long-standing applications have been tried, 
will settle down to the level of the dot-and-dash line. Thus, in start- 
ing a high-speed photographic activity, one must not expect the de- 
vice used to maintain the high level of its initial employment. 

Returning again to Table 1, there is portrayed opposite "Results" 
the condition where further changes in the device are necessary to get 



298 



E. M. WATSON 



Vol 43, No. 4 



the desired performance. As may be seen, this is the conclusion to 
be drawn after the data have been taken, prepared, and analyzed. 
The next step is to try to make the changes necessary in the device to 
accomplish the desired action. It is not always easy to decide just 
what to do in every instance, because sometimes inventive ability is 
not adequate for the occasion. However, it is necessary to do what- 




FIG. 6. 37- Mm gun mounted on turret truck for test 
firing. The elevator on which the camera is placed is ad- 
justable in height for various picture sizes. 



ever seems most desirable to accomplish what is needed. When 
these changes have been made, the device is again ready for more 
data to be taken and for the test cycle to be followed through again. 
It may be necessary to do this several times before arriving at a con- 
clusion of success or failure. If the changes accomplish the desired 
results, then it can be said that the job is complete so far as the pres- 
ent requirements are concerned, and success has been attained. On 
the other hand, it may be found that what is desired has not been 



Oct., 1944 FAST MOTION ANALYSIS 290 

accomplished, and it appears for the present there is little prospect of 
its being done. 

In order to make the most progress in the development of appara- 
tus, things to be done should include not only the obvious items but 
also those where the method of doing them can be found only by 
many trials, or may not even be possible until some subsequent de- 
velopment or invention provides the methods or material needed. 
Briefly, this means that not only the easy but the difficult things 
should be tried. Failure to get results by fast motion analysis 
may come from a number of things such as the fact that (1) meth- 
ods used in the analysis are not suitable for the kind of investigation 
at hand, (2} conditions believed to be present are found to be non- 
existent, and the discrepancy is due to some other cause, and (3) con- 




FIG. 7. 50-Caliber gun with window cut in side for viewing operation. 

ditions are found to exist for which no remedy can be immediately de- 
vised. 

High-speed pictures are best when the undesired motions looked for 
are fairly large and take up more than 5 per cent of the diameter of 
the picture area. There is considerable leeway, as there is a wide 
choice of picture area. In general, this method of analysis is best for 
reciprocating motions, where motions of parts are irregular and do 
not follow any well-defined path, or where articles are grasped, trans- 
ported and released. 

With reference to the analysis of fast motions, we find not only a 
problem in the technique of obtaining data but also a problem in the 
psychology of the minds of the people who are to use it. The latter 
perhaps is the more important, because it involves individuals as 
separate units, whereas technique once developed is usually univer- 
sally applicable. People vary in their background of experience and 
reaction to ideas. Getting various people together in a discussion 



300 E. M. WATSON Vol 43, No. 4 

might bring out some ideas which would never be thought of by these 
people individually. 

The data should be used in such a way that not only the individuals 
who are primarily interested have an opportunity to study them in 
order to utilize their abilities for the purpose of making improvements, 
but others who might possibly contribute ideas for the successful 
completion of the problem should also review the data. Under con- 
ditions of this kind it is very difficult to draw the line where diminish- 
ing returns in useful suggestions make attention from others, not 
primarily interested in the problem, unprofitable. 

In general, the data may be divided into 2 classes of special modifi- 
cations during the steps of apparatus development and regular opera- 
tions of standard apparatus. In the case of apparatus development, 




FIG. 8. Other side of same gun, showing viewing window. 

perhaps only a few people known to have worked on similar problems 
could profitably take working time to review the data. It must be 
recognized that with respect to the working time available, a choice 
of spending this time reviewing data and advising others materially 
handicaps one's own activity. 

In the case of regular operation of standard apparatus, it is of 
greater importance that people who are involved in the improvement 
and adaptation of this apparatus to specific jobs should study its 
operation. This interest may be not only in the establishment where 
the pictures are taken but at many other establishments where de- 
sign work is done, where the devices are manufactured, and where 
they are fitted as component units in the assembly of larger pieces of 
apparatus in which they will have their ultimate use. 

It often happens that at establishments other than those where the 
pictures or data were taken few people have any idea of the conditions 
under which they were taken. It is always well to have adequate 



Oct., 1944 FAST MOTION ANALYSIS 301 

general views, in addition to those showing the data, in order that 
people unfamiliar with surroundings will have the preface necessary to 
a fuller understanding of the fast motion analysis to follow. When 
the data are in the form of still pictures or curves, stills might be used to 
show the surroundings. When the data are in the form of high-speed 
motion pictures, there is an excellent opportunity to use, with little 
trouble and expense, the old silent picture technique of explaining, by 
means of titles and normal speed views, the important items to observe 
in the high-speed motion pictures to follow. 

A condition to be avoided is the disturbing of the peace of mind of 
those in charge of projects being studied by others who may attempt 
to improve their standing at the expense of those in charge of the 
projects. In showing pictures to others, there should never be the 
thought that the necessity for taking the pictures indicated inability 
of the people for whom they were taken to solve their problem without 
aid. There should be no appearance of change in the responsibility 
as to who decides what should be done in the program of trying vari- 
ous modifications thought profitable. All suggestions and interpreta- 
tions of things seen should clear through the people who are directly 
responsible for carrying out the program of improvement. 

Conditions here are different from those usually encountered. Or- 
dinarily the person in charge knows what is to be done by reason of 
having previous experience in less responsible positions and can direct 
the work accordingly. Where inventive work is done, the person 
looking after it can only try to encourage excursions of the minds of 
those in his group into fields which are entirely strange to him. A 
person's efficiency in routine jobs may not be greatly affected when 
he is annoyed by conditions about him, but creative work is inesti- 
mably handicapped when the minds of the people involved are dis- 
turbed. 

High-speed motion pictures have a unique application in training 
films. For the most part in training films normal-speed motion pic- 
tures are used to show the latest and most advanced procedure in 
order that the trainees may repeat this procedure when practicing 
with the actual pieces of equipment previously viewed. Under these 
conditions there is sufficient time for mental reactions to take place as 
the trainee adjusts his procedure, using actual equipment, in an ef- 
fort to follow the approved procedure previously demonstrated. 

Action which may require several seconds to show, but which takes 
place in a fraction of a second, happens too fast for anyone to make a 



302 E. M. WATSON 

decision while it is under way. The showing of such fast action may 
give the viewer a better knowledge of performance of devices he must 
use, thus increasing his confidence, but unless several situations are 
shown illustrating the effect of proper and improper preparation be- 
fore the fast action is caused to take place, there will be little training 
value derived. In some instances normal-speed views of proper and 
improper preparation followed by fast action pictures showing the 
results therefrom will have training value. 

Much of this procedure has not been tried sufficiently to be able to 
say that final conclusions can be drawn. It is to some extent a case 
where the methods of performing the experiment are still experimen- 
tal, and constructive criticism on the part of those involved may be 
very helpful in determining further refinements in methods. 

REFERENCE 

1 WATSON, E. M.: "Aids for Pictorially Analyzing High-Speed Action," /. Soc. 
Mot. Pict. Eng., 43, 4 (Oct., 1944), p. 267. 



TECHNICAL NEWS 



The items appearing in this section were submitted August 22, 1944, by mem- 
bers of the Technical News Committee, who welcome and will consider items of 
current technical interest from any member of the Society. 

Additional information concerning these items, or the equipment and processes 
discussed, may be obtained by communicating with the General Office of the 
Society, Hotel Pennsylvania, New York 1, N. Y. 

COLOR 

Extensive tests are being carried on in Hollywood with Ansco 
color process, even to the point of building special printers and 
other equipment. 

SOUND 

Warner Bros. Pictures, Inc. When sound tracks are recorded for 
playback or cuing only, no prints are made and the negative is 
played back through the film playback equipment. 

Sound Services, Inc. A vocal booth, which can be folded against 
the stage wall when not in use, is a feature of Sound Services scoring 
stage. A number of large panels capable of being arranged to form 
various enclosures are suspended from the roof trusses on rails so 
they may be easily moved. The possibility of simulating a number 
of acoustic conditions has proved of value in post-synchronizing 
work. 

Eastman Kodak Co. A new Eastman 35-mm variable-area sound 
recording negative film, code 1372, was placed on sale in Hollywood 
and New York during the month of August, 1944. This is a fine- 
grain, high resolving power emulsion of characteristics normally de- 
sired by variable-area sound recordists. 

TELEVISION 

A large number of television station applications have been re- 
ceived by the Federal Communications Commission from Southern 
California. Eight commercial applications are on file, with the 
possibility of a few more. The newest entry into the field is Warner 
Brothers. The Broadcasting Corporation of America of Riverside 

303 



304 TECHNICAL NEWS 

is also a newcomer. The National Broadcasting Company, as well 
as Warner Brothers, and Broadcasting Corporation of America all 
seek Channel 3. The Howard Hughes organization is in line for 
Channel 2. The Earl Anthony application is for Channel 6. Tele- 
vision Productions, the Paramount affiliate, is in operation on Chan- 
nel 4, while the Don Lee Broadcasting System is operating on Chan- 
nel 1. The Consolidated Broadcasting Corporation, Ltd., has ap- 
plied in Los Angeles for Channel 7. 

CAMERA EQUIPMENT 

Republic Pictures Corp. A combination line and buckle switch 
for camera motors, which performs both functions, has been de- 
veloped at Republic Studios. The new switch has a positive action 
when the trigger is released by a rod actuated when abnormal condi- 
tions of the film loop occur in the camera. 

Warner Bros. Pictures, Inc. Warner Brothers have purchased 
the Camera Division of the California Telephone and Electric Com- 
pany. This subsidiary is known as the American Camera Company 
and is now manufacturing the Cunningham Combat Cameras for 
the Armed Forces. Col. Nathan Levinson is president of the new 
company. 

CINEMATOGRAPHY 

Owing to the present technique in most studios of shooting many 
scenes, especially close-ups, with extremely wide-angle lenses and with 
actors in close proximity to the camera, some of the latest cameras 
are not sufficiently quiet to permit recording low-level dialogue. 
When these same cameras are used for average shots with 40-, 50- or 
75-mm lenses, they are satisfactory. Now with the use of 24-, 25- 
and 28-mm lenses for close angles, the microphone must be used too 
close to the camera for good sound. One major studio is considering 
the possibility of "blimping" their latest model cameras. 

In the production of Wilson certain old newsreel shots were used 
showing President Wilson riding through the streets of Paris and 
London. Since no close-ups were available, it was necessary for 
the producers to "shoot" black-and-white "close-ups" for inter-cut- 
ting in this old footage. This was done very successfully by flat- 
lighting the subject and using an old model Pathe camera for the 
photography. 



COMMITTEES OF THE SOCIETY 

(Correct to September 15) 



The Board of Governors voted recently to publish in the JOURNAL regularly the 
personnel and scope of all standing committees of the Society. It is believed 
these data will be of value not only to committee chairmen and members in having 
an up-to-date list of committee membership, but will be of interest to others who 
may be unfamiliar with the general nature of activities engaged in by the various 
technical and nontechnical committees of the Society. 



ADMISSIONS. To pass upon all applications for membership, applications for transfer and 
to review the Student and Associate membership list periodically for possible transfers to the 
Associate and Active grades respectively. The duties of each committee are limited to applica- 
tions and transfers originating in the geographic area covered. 

(East Coast) 
A. S. DICKINSON, Chairman 

28 West 44th St. 
New York 18, N. Y. 

M. R. BOYER JAMES FRANK, JR. D. E. HYND .TAN 

H. D. BRADBURY GEORGE FRIEDL, JR. HARRY RUBIN 

(West Coast) 
4 EMERY HUSE, Chairman 

6706 Santa Monica Blvd. 
Hollywood 38, Calif. 

C. W. HANDLEY W. A. MUELLER 

H. W. MOYSE H. W. REMERSHIED 

BOARD OF EDITORS. To pass upon the suitability of all material submitted for publica- 
tion, or for presentation at conventions, and publish the JOURNAL. 

A. C. DOWNES, Chairman 

Box 6087 
Cleveland 1, Ohio 

J. I. CRABTREE A. M. GUNDELFINGER C. R. KEITH 

A. N. GOLDSMITH C. W. HANDLEY E. W. KELLOGG 

A. C. HARDY 

CINEMATOGRAPHY. To survey the field of motion picture photography in an en- 
deavor to bring before the Society any information on current or future practice, and also to 
continually review this field for possibilities of standardization of any specific procedure. 

J. W. BOYLE, Chairman 

1207 N. Mansfield Ave. 
Hollywood, Calif. 

C. G. CLARKE *ARTHUR MILLER ARTHUR REEVES 

KARL FREUND JOSEPH RUTTENBERG 



Advisory Member. 

305 



306 COMMITTEES OF THE SOCIETY Vol 43, No. 4 

COLOR. To survey the field of color in motion picture photography in an endeavor to bring 
before the Society any information on current or future practice, and also to continually review 
this field for possibilities of standardization of any specific procedure. 

R. M. EVANS, Chairman 

Research Laboratory 
Eastman Kodak Co. 
Rochester 4, N. Y. 

F. T. BOWDITCH A. M. GUNDELFINGER 

L. E. CLARK A. C. HARDY 

CONVENTION. To assist the Convention Vice-President in the responsibilities pertaining 
to arrangements and details of the Society's technical conventions. 

W. C. KUNZMANN, Chairman 

Box 6087 
Cleveland 1, Ohio 

J. G. FRAYNE SYLVAN HARRIS O. F. NEU ^ 

*JULIUS HABER H. F. HEIDEGGER R. O. STROCK 

EXCHANGE PRACTICE. To survey the field of exchange practice in an endeavor to bring 
before the Society any information on current or future practice, and also to continually review 
this field for possibilities of standardization of any specific procedure. 

A. S. DICKINSON G. K. HADDOW N. F. OAKLEY 

*T. FAULKNER SYLVAN HARRIS A. W. SCHWALBERG 

G. R. GIROUX L. B. ISAAC J. SICHELMAN 

H. C. KAUFMAN 

FELLOW MEMBERSHIP. To consider qualifications of Active members as candidates for 
elevation to Fellow members, and to submit such nominations to the Board of Governors. 

EMERY HUSE, Chairman 

6706 Santa Monica Blvd. 
Hollywood 38, Calif. 

M. R. BOYER A. N. GOLDSMITH W. C. KUNZMANN 

A. S. DICKINSON HERBERT GRIFFIN L. L. RYDER 

A. C. DOWNES C. W. HANDLEY E. A. WILLIFORD 

D. E. HYNDMAN 

HISTORICAL AND MUSEUM. To collect facts and assemble data relating to the historical 
development of the motion picture industry, to encourage pioneers to place their work on record 
in the form of papers for publication in the JOURNAL, and to place in suitable depositories equip- 
ment pertaining to the industry. 

J. E. ABBOTT, Chairman 

11 West 53d St. 
New York 19, N. Y. 

O. B. DEPUE RICHARD GRIFFITH TERRY RAMSAYE 

HONORARY MEMBERSHIP. To diligently search for candidates who through their 
basic inventions or outstanding accomplishments have contributed to the advancement of the 
motion picture industry and are thus worthy of becoming Honorary members of the Society. 

E. A. WILLIFORD, Chairman 

30 East 42d St. 
New York 17, N. Y. 

J. I. CRABTREE EMERY HUSE 

A. N. GOLDSMITH L. L. RYDER 






* Advisory Member. 



Oct., 1944 COMMITTEES OF THE SOCIETY 307 

JOURNAL AWARD. To recommend to the Board of Governors the author or authors of 
the most outstanding paper originally published in the JOURNAL during the preceding calendar 
year to receive the Society's Journal Award. 

SYLVAN HARRIS, Chairman 

8621 Georgia Ave. 
Silver Spring, Md. 

F. G. ALBIN C. R. KEITH 

J. G. FRAYNE J. A. MAURER 

LABORATORY PRACTICE. To survey the field of motion picture laboratory practice in 
an endeavor to bring before the Society any information on current or future practice, and also 
to continually review this field for possibilities of standardization of any specific procedure. 

H. E. WHITE, Chairman 

Room 813 

350 Madison Ave. 

New York 17, N. Y. 

A. C. BLANEY G. H. GIBSON J. M. NICKOLAUS 

L. A. BONN EMERY HUSE N. F. OAKLEY 

A. W. COOK T. M. INGMAN W. H. OFFENHAUSER, JR. 

O. B. DEPUE C. L. LOOTENS V. C. SHANER 

R. O. DREW *A. J. MILLER J. H. SPRAY 

J. A. DUBRAY H. W. MOYSE J. F. VAN LEUVEN 

J. G. FRAYNE J. R. WILKINSON 

MEMBERSHIP AND SUBSCRIPTION. To solicit new members, obtain nonmember sub- 
scriptions for the JOURNAL, and to arouse general interest in the activities of the Society and its 
publications. 

JAMES FRANK, JR., Chairman 

356 West 44th St. 
New York 18, N. Y. 

T. C. BARROWS E. R. GEIB W. A. MUELLER 

J. G. BRADLEY L. T. GOLDSMITH H. B. SANTEE 

KARL BRENKERT SYLVAN HARRIS G. E. SAWYER 

G. A. CHAMBERS L. B. ISAAC W. L. THAYER 

L. W. CHASE W. C. KUNZMANN *C. R. WOOD 

J. P. CORCORAN S. A. LUKES E. O. WILSCHKE 

J. G. FRAYNE G. E. MATTHEWS W. V. WOLFE 
G. C. MISENER 



NONTHEATRICAL EQUIPMENT. To survey the field of nontheatrical motion picture 
equipment in an endeavor to bring before the Society any information on current or future prac- 
tice, and also to continually review this field for possibilities of standardization of any specific 
procedure. 

J. A. MAURER, Chairman 

117 East 24th St. 
New York 10, N. Y. 

*F. L. BRETHAUER R. C. HOLSLAG *T. J. RESS 

F. E. CARLSON R. KINGSLAKE L. T. SACHTLEBEN 

JOHN CHRISTIE D. F. LYMAN A. SHAPIRO 

R. O. DREW W. H. OFFENHAUSER, JR. D. G. SMITH 

F. M. HALL M. W. PALMER M. G. TOWNSLEY 

J. A. HAMMOND A. G. ZIMMERMAN 



Advisory Member 



308 COMMITTEES OF THE SOCIETY Vol 43, No. 4 

PAPERS. To solicit papers, and provide the program for semi-annual conventions, and make 
available to local sections for their meetings papers presented at national conventions. 

BARTON KREUZER, Chairman 

RCA Victor Division 
Radio Corp. of America 
Camden, N. J. 

C. R. DAILY, Vice- Chairman 

5451 Marathon St. 
Hollywood 38, Calif. 

F. T. BOWDITCH JAMES FRANK, JR. H. W. MOYSE 

G. A. CHAMBERS J. G. FRAYNE V. C. SHANER 
F. L. EICH C. R. KEITH S. P. SOLOW 
R. E. FARNHAM E. W. KELLOGG D. R. WHITE 
J. L. FORREST G. E. MATTHEWS W. V. WOLFE 

P. A. McGuiRE 

PRESERVATION OF FILM. To survey the field for methods of storing and preserving mo- 
tion picture film in an endeavor to bring before the Society any information on current or future 
practice, and also to continually review this field for possibilities of standardization of any specific 
procedure. 

J. G. BRADLEY, Chairman 

The National Archives 
Washington 25, D. C. 

J. E. ABBOTT J. L. FORREST *W. F. KELLEY 
J. I. CRABTREE C. L. GREGORY TERRY RAMSAYE 
A. S. DICKINSON V. B. SEASE 



PROCESS PHOTOGRAPHY. To survey the field of process photography in an endeavor 
to bring before the Society any information on current or future practice, and also to continually 
review this field for possibilities of standardization of any specific procedure. 

WILLIAM THOMAS, Chairman 

851 Monterey Rd. 
Glendale, Calif. 

F. R. ABBOTT *F. M. FALGE GROVER LAUBE 

A. H. BOLT C. W. HANDLEY G. H. WORRALL 

W. C. HOCH 

PROGRESS. To prepare an annual report on progress in the motion picture industry. 

G. A. CHAMBERS, Chairman 

Naval Air Station, PSL 
Anacostia, D. C. 

F. T. BOWDITCH J. A. DUBRAY G. E. MATTHEWS 

G. L. DIMMICK M. S. LESHING D. R. WHITE 

PROGRESS MEDAL AWARD. To recommend to the Board of Governors a candidate who 
by his inventions, research or development has contributed in a significant manner to the 
advancement of motion picture technology, and is deemed worthy of receiving the Progress 
Medal Award of the Society. 

J. I. CRABTREE, Chairman 

Research Laboratory 
Eastman Kodak Co. 
Rochester 4, N. Y. 

O. B. DEPUE J. A. MAURER 

G. E. MATTHEWS L. L. RYDER 



Advisory Member. 



Oct., 1944 



COMMITTEES OF THE SOCIETY 



309 



PUBLICITY. To assist the Convention Vice-President in the release of publicity material 
concerning the Society's semi-annual technical conventions. 

"JULIUS HABER, Chairman 

RCA Victor Division 
Radio Corp. of America 
Camden, N. J. 



G. A. CHAMBERS 
C. R. DAILY 



*HAROLD DESFOR 



G. R. GIROUX 
P. A. McGuiRE 



SOUND. To survey the field of motion picture sound recording and reproducing in an en- 
deavor to bring before the Society any information on current or future practice, and also to con- 
tinually review this field for possibilities of standardization of any specific procedure. 

W. V. WOLFE, Chairman 

515 N. Alta Drive 
Beverly Hills, Calif. 

C. R. KEITH, Vice- Chair man 

195 Broadway 
New York 7, N. Y. 



M. C. BATSEL 
D. J. BLOOMBERG 

B. B. BROWN 

F. E. CAHILL, JR. 

C. R. DAILY 

L. T. GOLDSMITH 



E. H. HANSEN 
L. B. ISAAC 
J. P. LIVADARY 

G. T. LORANCE 

J. A. MAURER 
W. C. MILLER 
K. F. MORGAN 



W. A. MUELLER 
HARRY RUBIN 
G. E. SAWYER 
S. P. SOLOW 
F. R. WILSON 
*E. C. ZRENNER 



STANDARDS. To survey the various fields or branches of the motion picture industry in an 
endeavor to bring before the Society any information on current or future practice or methods 
that would lead to possibilities of standardization of any specific procedure. 



J. M. ANDREAS 
P. H. ARNOLD 
HERBERT BARNETT 
M. C. BATSEL 
M. R. BOYER 
F. E. CARLSON 
*T. H. CARPENTER 
E. K. CARVER 

H. B. CUTHBERTSON 

L. W. DAVEE 

J. A. DUBRAY 



F. T. BOWDITCH, Chairman 

Box 6087 
Cleveland 1, Ohio 



A. F. EDOUART 
J. L. FORREST 
A. N. GOLDSMITH 
L. T. GOLDSMITH 
HERBERT GRIFFIN 
A. C. HARDY 
D. B. JOY 
C. R. KEITH 
P. J. LARSEN 

R. G. LlNDERMAN 

C. L. LOOTENS 
J. A. MAURER 



G. A. MITCHELL 

W. H. OFFENHAUSER, JR. 

G. F. RACKETT 

W. B. RAYTON 

HARRY RUBIN 

L. T. SACHTLEBEN 

OTTO SANDVIK 

LLOYD THOMPSON 

J. F. VAN LEUVEN 

H. E. WHITE 

A. G. ZIMMERMAN 



STUDIO LIGHTING. To survey the field of motion picture studio lighting in an endeavor 
to bring before the Society any information on current or future practice, and also to continually 
review this field for possibilities of standardization of any specific procedure. 



J. W. BOYLE 
H. J. CHANON 



C. W HANDLEY, Chairman 

I960 West 84th St. 
Los Angeles 44, Calif. 

R. E. FARNHAM 



KARL FREUND 
W. W. LOZIER 



* Advisory Member. 



310 



COMMITTEES OF THE SOCIETY 



Vol 43, No. 4 



TECHNICAL NEWS. To survey the fields of production, distribution, and exhibition of 
motion pictures, and allied industries, to obtain technical news items for publication in the 
JOURNAL. 



J. W. BOYLE 
J. I. CRABTREE 

A. M. GUNDELFINGER 



A. C. BLANEY, Chairman 

1016 N. Sycamore St. 
Hollywood 38, Calif. 

C. W. HANDLEY 
EMERY HUSE 
H. R. LUBCKE 



K. F. MORGAN 

H. W. REMERSHIED 

WILLIAM THOMAS 



TELEVISION. Technical consideration of the uses of motion picture television service; 
technical consideration of the phases of television which affect origination, transmission, dis- 
tribution, and reproduction of theater television. 

P. C. GOLDMARK, Chairman 

485 Madison Ave. 
New York 22, N. Y. 



R. B. AUSTRIAN 
R. L. CAMPBELL 
E. D. COOK 
C. E. DEAN 
A. N. GOLDSMITH 
T. T. GOLDSMITH 
HERBERT GRIFFIN 
C. F. HORSTMAN 



L. B. ISAAC 
A. G. JENSEN 
P. J. LARSEN 
C. C. LARSON 
NATHAN LEVINSON 
H. R. LUBCKE 
*I. G. MALOFF 



J. A. MAURER 
PIERRE MERTZ 
*PAUL RAIBOURN 
P. H. Hiss 
OTTO SANDVIK 
R. E. SHELBY 
E. I. SPONABLE 
H. E. WHITE 



TEST FILM QUALITY. To supervise the quality of prints of test films prepared by the 
Society. 



F. R. WILSON 



C. F. HORSTMAN 



THEATER ENGINEERING. The Committee on Theater Engineering comprises the 
membership of the four subcommittees listed below and is under the general chairmanship of 
DR. ALFRED N. GOLDSMITH, 597 Fifth Ave., New York 17, N. Y. 



Subcommittee on Film Projection Practice. To make recommendations and prepare specifi- 
cations for the operation, maintenance, and servicing of motion picture projection equipment, 
projection rooms, film storage facilities, and stage arrangements as they affect screen dimen 
sions, placement, and the maintenance of loudspeakers. 



L. B. ISAAC, Chairman 
M. D. O'BRIEN, Secretary 

1540 Broadway 
New York 19, N. Y. 



HENRY ANDERSON 
T. C. BARROWS 
H. D. BEHR 
M. F. BENNETT 
KARL BRENKERT 
F. E. CAHILL, JR. 
C. C. DASH 
L. W. DAVEE 
A. S. DICKINSON 



J. K. ELDERKIN 
JAMES FRANK, JR. 
R. R. FRENCH 
E. R. GEIB 
ADOLPH GOODMAN 
HERBERT GRIFFIN 
SYLVAN HARRIS 
J. J. HOPKINS 
C. F. HORSTMAN 
I. JACOB SEN 



*J. H. LlTTENBERG 

E. R. MORIN 
J. R. PRATER 
HARRY RUBIN 
J. J. SEFING 
R. O. WALKER 
V. A. WELMAN 
H. E. WHITE 
A. T. WILLIAMS 



Oct., 1944 COMMITTEES OF THE SOCIETY 311 

Subcommittee on Television Projection Practice. To make recommendations and prepare 
specifications for the construction, installation, maintenance, and servicing of equipment for 
projecting television pictures in the theater, as well as the projection room arrangements neces- 
sary for such equipment, and such picture-dimensional and screen-characteristic matters as 
may be involved in theater television presentation. 

L. B. ISAAC, Chairman 
M. D. O'BRIEN, Secretary 

1540 Broadway 
New York 19, N. Y. 

(Under organization) 

Subcommittee on Screen Brightness. To make recommendations, prepare specifications 
and test methods for determining and standardizing the brightness of the motion picture screen 
image at various parts of the screen, and for specific means or devices in the projection room 
adapted to the control or improvement of screen brightness. 

F. E. CARLSON, Chairman 

Nela Park 
Cleveland 12, Ohio 

HERBERT BARNETT W. F. LITTLE C. M. TUTTLE 

E. R. GEIB W. B. RAYTON H. E. WHITE 

SYLVAN HARRIS A. T. WILLIAMS 

Subcommittee on Theater Engineering, Construction, and Operation. To deal with the 
technical methods and equipment of motion picture theaters in relation to their contribution for 
the physical comfort and safety of patrons so far as can be enhanced by correct theater design, 
construction, and operation of equipment. 

(Under organization) 



MEMBERS OF THE SOCIETY 

LOST IN THE SERVICE OF 

THEIR COUNTRY 



FRANKLIN C. GILBERT 



ISRAEL H. TILLES 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

Vol43 NOVEMBER, 1944 No. 5 

CONTENTS 

PAGE 

Noise-Reduction Anticipation Circuits J. G. FRAYNE 313 

The Eastman High-Speed Camera, Type III 

J. L. BOON 321 

An AAF Portable Sound Recording Unit F. T. DYKE 327 

The Training Film Formula O. GOLDNER 334 

The Training Film an Instrument for the Control of 

Human Behavior H. B. ROBERTS 344 

Treatment of Navy Slide Films for Psychologic Impact 

. J. DRESSER 352 

Getting the Most for the Navy Training Film Dollar 

L. R. GOLDFARB 357 

It is to Laugh J. E. BAUERNSCHMIDT 366 

The Camera versus the Microphone in Training Film 

Production H. R. JENSEN 372 

Current Literature 377 

Society Announcements 378 
(The Society is not responsible for statements of authors.) 

Contents of previous issues of the JOURNAL are indexed in the 
Industrial Arts Index available in public libraries. 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

HARRY SMITH, JR., EDITOR 

ARTHUR C. DOWNES, Chairman 

Board of Editors 

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KELLOGG 
CLYDE R. KEITH ALAN M. GUNDELFINGER CHARLES W. HANDLEY 

ARTHUR C. HARDY 
Officers of the Society 
*President: HERBERT GRIFFIN, 

133 E. Santa Anita Ave., Burbank, Calif. 

* Past-President: EMERY HUSE, 

6706 Santa Monica Blvd., Hollywood, Calif. 
*Executive Vice-President: LOREN L. RYDER, 

6451 Marathon St., Hollywood, Calif. 
** Engineering Vice- President: DONALD E. HYNDMAN, 

350 Madison Ave., New York, N. Y. 
*Editorial Vice-President: ARTHUR C. DOWNES, 

Box 6087, Cleveland, Ohio. 
**Financial Vice-President: ARTHUR S. DICKINSON, 

28 W. 44th St., New York, N. Y. 

* Convention Vice-President: WILLIAM C. KUNZMANN, 
Box 6087, Cleveland, Ohio. 

* Secretary: E. ALLAN WILLIFORD, 

30 E. 42d St., New York, N. Y. 
^Treasurer: M. R. BOYER 

350 Fifth Ave., New York, N. Y. 

Governors 

**FRANK E. CARLSON, Nela Park, Cleveland, Ohio. 
*fCHARLES W. HANDLEY, 1960 W. 84th St., Los Angeles, Calif. 
**EDWARD M. HONAN, 6601 Romaine St., Hollywood, Calif. 
* {CLYDE R. KEITH, 195 Broadway, New York, N. Y. 
**JOHN A. MAURER, 117 E. 24th St., New York, N. Y. 
*HOLLIS W. MOY^E, 6656 Santa Monica Blvd., Hollywood, Calif. 
*WILLIAM A. MUELLER, 4000 W. Olive Ave., Burbank, Calif. 
*H. W. REMERSHIED, 716 N. La Brea St., Hollywood, Calif. 
**EARL I. SPONABLE, 460 W. 54th St., New York, N. Y. 

* JOSEPH H. SPRAY, 1277 E. 14th St., Brooklyn, N. Y. 
*REEVE O. STROCK, 111 Eighth Ave., New York, N. Y. 

"WALLACE V. WOLFE, 1016 N. Sycamore St., Hollywood, Calif. 

*Term expires December 31, 1944. 
**Term expires December 31, 1945. 
tChairman, Pacific Coast Section. 
jChairman, Atlantic Coast Section. 



Subscription to non members, $8.00 per annum; to members, $5.00 per annum, included 

in their annual membership dues; single copies, $1.00. A discount on subscription or single 

copies of 15 per cent is allowed to accredited agencies. Order from the Society of Motion Picture 

Engineers, inc., Hotel Pennsylvania, New York 1, N. Y. Telephone No. PEnnsylvania 6-0620. 

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers, Inc. 

Publication Office, 20th & Northampton Sts., Easton, Pa. 

General and Editorial Office, Hotel Pennsylvania, New York 1, N. Y. 

Entered as second-class matter January 15, 1930, at the Post Office at Easton, 

Pa., under the Act of March 3, 1879. Copyrighted, 1944, by the Society of Motion 

Picture Engineers. Inc. 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

Vol 43 NOVEMBER, 1944 No. 5 

NOISE-REDUCTION ANTICIPATION CIRCUITS* 
JOHN G. FRAYNE** 



Summary. The use of an additional microphone to provide an anticipation 
signal to operate noise-reduction circuits is described, the anticipation microphone 
being placed ahead of the signal microphone by sufficient distance so that the noise- 
reduction element in a modulator is fully opened to permit recording of the maximum 
signal amplitude. In rerecording a special hill-and-dale record is made of the last 
rehearsal. This record is then played back during the take, the output being fed to 
the noise-reduction circuit and anticipation being accomplished by moving the needle 
ahead on the disk by an appropriate distance. 

The clipping of the initial waves in a sound sequence in recording 
systems employing noise-reduction circuits is well known, and sev- 
eral concrete suggestions have been put forth by various writers with 
a view to eliminating this effect. Attention was first called to this 
effect by Silent and Frayne 1 who suggested the use of a delay circuit 
in the signal channel. The difficulties involved in designing such a 
delay circuit, and the expense involved in applying it to production 
recording, have been discussed in -some detail by Kellogg. 2 So far as 
is known, no actual attempt has been made to use a delay circuit in 
the sound channel, chiefly because all of the devices proposed, 
whether artificial line, acoustic tube, magnetic tape recorder and 
playback, add some distortion to the sounds being recorded. 

The most successful attack on the problem of clipping is the scheme 
described by Dimmick and Blaney 3 in their method of so-called 
"direct-positive recording." The noise reduction is attained by an 
auxiliary light beam which operates on the film after it has passed 
the recording light beam. Since this track resembles a positive made 
.from a negative to which noise reduction had been applied, no further 
prints can be made without resorting to photographic duplication 

* Presented Apr. 18, 1944, at the Technical Conference in New York. 
** Electrical Research Products Division, Western Electric Company, Holly- 
wood. 

313 



314 J. G. FRAYNE Vol 43, No. 5 

Kellogg 2 points out that this method is not applicable to variable den- 
sity by any known methods. 

For variable-density records anticipation can be accomplished in 2 
ways, either by incorporating the signal delay circuit referred to 
above, or providing means for impressing the input signal on the 
noise-reduction circuit ahead of the signal being applied to the light 
valve by a time interval equal to that required for the operation of 
the noise-reduction circuit. The latter can be accomplished by using 
2 microphones in line with the sound source, the microphone nearest 
the sound being used to supply the input to the noise-reduction cir- 
cuit, while the other microphone supplies the signal in the normal 
manner to the modulating device. The use of 2 microphones was sug- 
gested by Fletcher 4 in connection with the operation of the compandor 
circuits used in making the stereophonic recordings. In this case the 
advance microphone supplied an input to the compressor, in order to 
reduce the gain of the signal channel in sufficient time to accommo- 
date the incoming signal of increased amplitude. So far as is known 
to the author, the use of a separate microphone to actuate a channel 
employing noise reduction was not employed previous to its recent 
use by the Electrical Research Products Division of Western Electric 
Company, Inc., in connection with the recording of steep wave front 
sounds. 

While the over-all improvement obtained by employment of antici- 
pation is similar, whether applied to a compandor or to a noise-re- 
duction circuit, the mechanism of obtaining the improvement is to- 
tally different in the 2 cases. In the compandor the gain of a recording 
channel is controlled in advance, while in the noise-reduction case the 
capacity of the modulating device, or light valve, is increased in ad- 
vance of the incoming signal. In the compandor no change is made 
in the mean transmission changes in advance in accordance with the 
envelope of the sound being recorded. 

A simplified schematic of this noise-reduction anticipation record- 
ing channel is shown in Fig. 1. The 2 microphones are shown at the 
left followed by 2 similar 120-B preamplifiers. A special ganged 
mixer position is supplied which enables the mixer to control equally 
the gain of both speech and anticipation channel by the rotation of 
one single dial, the output of each potentiometer in the gang being 
fed, respectively, into the appropriate signal and control channels. 

In operation the signal microphone is first placed at the position 
dictated by the requirements of the pickup, that is, close-up, me- 



Nov., 1944 NOISE-REDUCTION ANTICIPATION CIRCUITS 



315 



diuni, or distant, the control microphone being placed about 10 ft in 
front of the signal microphone and in line with the source of sound. 
The 10-ft distance was determined by multiplying the speed of sound 
of approximately 1100 ft per sec and the operating time of 0.009 sec 
of the noise-reduction circuit. Having placed the microphones in 
their proper relation to the source of sound, the calibration of the 2 
channels was made by setting up a loudspeaker at the sound source to 
which was fed a 400-cycle tone. The output of the 124 amplifier in 
the signal channel was first measured on the volume indicator. The 
output of the 120 amplifier in the control channel after passing 
through the high pass filter was then patched into the input of the 




FIG. 1. 



limiting amplifier in the signal channel, thus, lifting off the tone from 
the signal circuit. The volume indicator was then read again and the 
gain of the anticipation channel varied by the 30 db potentiometer 
immediately in front of the 120-B amplifier until the 2 readings on 
the volume indicator were identical. Since the 120 amplifiers in the 
signal and control channels had previously been checked for equal 
gain, equal readings on the volume indicator for the 2 conditions 
mentioned showed equal sensitivity for the 2 circuits from their re- 
spective microphone positions. Under some pickup conditions, es- 
pecially when the sound source was not well localized, "margin" of 
one or 2 db was used in the noise-reduction channel. 

Recordings made in this manner of steep wave front sounds showed 
a degree of sharpness not usually associated with recordings of this 
nature. An unexpected improvement was a complete absence of 



316 



J. G. FRAYNE 



Vol 43, No. 5 



"hush-hush" which normally is associated with recordings of this 
type. Results of the initial recordings showed such an improvement 
in these respects that this technique was continued throughout the 
project. 

ANTICIPATION IN RERECORDING 

: t * * 

It was considered desirable to retain in the rerecording process as 
much as possible of the sharpness achieved in recording the original 
steep wave front sounds. It was conceded that the ideal method of 
obtaining anticipation in a rerecording channel would be to employ an 



REPRODUCER 
PEC AMPL. 




FIG. 2. 



advance scanning slit in each rerecording dummy, the spacing between 
this slit and the customary translation point being determined by the 
operating time of the noise-reduction circuit used in making the re- 
recorded negative. This method was disclosed in I). S. Patent 2,096,- 
811 issued in 1937 to E. W. Kellogg. Since the rerecording operation 
involves a great many dummies, the provision of extra slits with their 
associated amplifiers and mixing controls would add considerable 
complexity to an operation which is already highly involved. 

An alternative of this scheme was employed in making the rere- 
cordings, the circuit schematic being shown in Fig. 2, which is a sim- 
plified form of the rerecording setup. Here, the output of the indi- 
vidual dummies is combined in the usual manner and may be fed into 



Nov., 1944 NOISE-REDUCTION ANTICIPATION CIRCUITS 317 

either a disk recorder, or a film recorder, or both. After rehearsing 
the operation a sufficient number of times to insure correct synchroni- 
zation and balance of the individual sounds, a hill-and-dale wax play- 
back was recorded. Following the making of the wax record, the 
output of the latter was patched into the input of the anticipation 
channel in a manner similar to the output of the anticipation micro- 
phone used in making the original sound tracks. The anticipation 
was provided by moving the reproducing needle along the groove by 
a distance from the starting point so that the corresponding time in- 
terval equaled the operating time of the noise-reduction circuit. A 
push-pull recording was then made on film, the output of the play- 
back being applied to supply signal to the noise-reduction circuit. 



r 



ANTICIPATION 



ANTICIPATION IN NOISE 
REDUCTION CIRCUIT 



FIG. 3. 



To insure that the playback level was correct for operating the noise 
reduction, a recording from a 400-cycle push-pull film loop had first 
been made on the disk. The film output from this loop and the out- 
put from the wax playback made from it were then fed, respectively, 
into the signal and anticipation channels and the gain adjusted until 
equal sensitivity was attained. 

For completely correct operation of this anticipation technique it 
would be necessary that the signal amplitudes on the recorded take 
be very close at all times to those used in previously making the play- 
back. With manual operation of the mixing dials this is, of course, 
difficult to achieve, but the levels in the 2 cases were apparently close 
enough at all times so that no apparent trouble was encountered from 
operating the noise reduction in this manner. Listening tests proved 
that rerecordings made thus preserved the sharpness of attack "sounds 



318 



J. G. FRAYNE 



Vol 43, No. 5 



of the original records and were far superior to a push-pull rere- 
cording track made employing noise reduction in the customary man- 
ner. 

The photographic reproduction of 2 rerecorded tracks shown in 
Fig. 3 illustrates very clearly the opening of the noise-reduction cir- 
cuit in advance of the signal. It will be seen that when anticipation 




FIG. 4. 



is used the transmission of the print begins to increase about one 
sprocket hole in advance of the first pulse, whereas in the standard 
condition the track remains dark up to the initial pulse. The photo- 
micrographs, Figs. 4 and 5, show, respectively, the nature of the modu- 
lation without and with anticipation. In the first case the positive 
phase of the increasing signal is recorded normally by one of the com- 
ponent push-pull valves, while the negative phase is clipped. It will 
be noticed that the light valve has failed to open until the first main 
part of the signal has been recorded. The initial sounds recorded in 
this manner have the appearance of a class B push-pull recording. 



Nov., 1944 NOISE-REDUCTION ANTICIPATION CIRCUITS 



319 



An examination of Fig. 5 (in which anticipation is employed) shows 
that the bias has now been removed before the first signal pulse ar- 
rives and both phases of the initial sounds are now recorded with a 
high degree of fidelity. 

Since the completion of this project U. S. Patent 2,341,303 was is- 
sued as of February 8, 1944, to W. V. Wolfe, which discloses the use 




FIG. 5. 



of a playback record to accomplish results comparable to those de- 
scribed in this paper. 

The success in recording steep wave front sounds when anticipation 
is employed leads inevitably to the conclusion that the recording of 
all manner of sound effects and certain types of muscial instruments 
would be greatly improved if the anticipation technique could be 
made available to the motion picture industry. However, the use of 
2 microphones placed about 10 ft apart presents an almost insur- 
mountable difficulty on recording stages owing to the limited space 
requirements. This condition can be alleviated, however, if a' 



320 J. G. FRAYNE 

quicker operating time of the noise-reduction circuit were made pos- 
sible. For example, an operating time of one millisecond would per- 
mit the microphones to be placed about one foot apart, thus making it 
possible to mount both of them from a single suspension and make 
possible simultaneous movement of both microphones by the micro- 
phone boom operator. Alternately, the reduction of operate time 
to around one millisecond might make a delay circuit of the artificial 
line type more feasible from the economic point of view. 

REFERENCES 

1 SILENT, H. C., AND FRAYNE, J. G.: "Western Electric Noiseless Recording," 
/. Soc. Mot. Pict. Eng., XVIII (May, 1932), p. 551. 

2 KELLOGG, E. W. : "Ground Noise-Reduction Systems," /. Soc. Mot. Pict. Eng , 
XXXVI (Feb., 1941), p. 137. 

3 DIMMICK, G. L., AND BL'ANEY, A. C.: "A Direct-Positive .System of Sound 
Recording," /. Soc. Mot. Pict. Eng., XXXIII (Nov., 1939), p. 479. 

4 FLETCHER, H.: "The Stereophonic Sound-Film System," /. Soc. Mot. Pict. 
Eng., XXXVII (Oct., 1941), p. 331. 



THE EASTMAN HIGH-SPEED CAMERA, TYPE III 
J. L. BOON* 

Summary. In the following article the Eastman Type III High-Speed Camera 
is briefly described, and particular emphasis is given to the improvements of this 
model over the Type II Camera in design and operation. 

The Eastman Type III High-Speed Camera is basically like its 
predecessor, the Type II Camera, in design and operation, but a 
number of changes and improvements have been made for the bene- 
fit of the user. 

The optical compensation principle has already been described in a 
paper published by Tuttle and Reid, 1 and a description of the Type II 
Camera has been published by Tuttle in the JOURNAL of December, 
1933. 2 

In the new model a universal type of motor has been continued, but 
the windings have been changed so that it is now possible to attain 
maximum speeds on 110 v without resorting to transformers. Lower 
voltages may be used, but slower maximum speeds will result. A 
dynamically balanced motor was chosen to reduce vibrations which 
might come from this source. Although definite evidence was lacking, 
it was believed that vibrations or deflections of the shaft would occur 
if the motor were coupled directly to the rotating compensator plate 
shaft. Consequently, it was decided to interpose an intermediate 
shaft between them, which also made it possible to separate the bear- 
ings on the rotating plate shaft so that a bearing could be placed at 
either end. With these improvements, the maximum camera speed 
was increased to 3000 pictures per sec, givmg a time magnification of 
approximately 200 when the film is viewed with a motion picture pro- 
jector running at normal speed. 

As a result of considerable tests and studies, the thin rotating flat 
of glass used as a compensator for the film motion was retained, along 
with the barrel-type shutter for limiting the angle of exposure (see 
Fig. 1). A new type of mounting was designed in which the glass 

* Eastman Kodak Company, Rochester, N. Y. 

321 



322 



J. L. BOON 



Vol 43, No. 5 



Lens 



Optical Plate 
with Shutters 



Film 








7---1 




1. Light coming from the lens is 
prevented from reaching the film by 
the shutter. 



2. After further rotation of the 
shutter and compensator unit, light 
rays from the lens are permitted to 
pass through to the film and are re- 
fracted upward. 



3 and 4. Continuation of the rota- 
tion during the exposure period. 



JPT5. The light, is again prevented 
from passing through to the film. The 
small arrows at the right illustrate the 
various displacements of the image 
formed by the lens; through the use 
of gears between the compensator 
shaft and the film sprockets, the film 
is advanced continuously at a rate 
which approximates the image dis- 
placement very closely. 

For the sake of clarity, only one light 
ray is shown in these illustrations. 



FIG. 1. Schematic drawing showing the rotating optical compensator and 

barrel- type shutter. 



Xov., 1944 THE EASTMAN HIGH-SPEWED CAMERA, TYPE III 323 

plate housing, the pinion for driving the film sprockets, and the shaft 
are machined from a single piece of steel. 

The same general plan of film path is retained in the Type III Cam- 
era (see Fig. 2) . The film travels from the supply spool over the up- 
per sprocket, past the film gate where the exposure is made, over the 
lower sprocket, and then to the take-up spool. The film gate is re- 
versed, however, so that it now touches the film backing instead of 
the emulsion, a change which retains a substantially flat focal plane 
at the exposure area. For ease of threading, the spring-mounted up- 




FIG. 2. Interior of Eastman Type III High-Speed Camera. 

per sprocket was improved so that its toothed portion is now limited 
in its motion relative to the directly driven inner portion. In this 
way possible damage to the spring is eliminated, as well as uncertainty 
regarding the exact amount of tension in the film across its gate. 

Excessive unwinding of the film on the supply spool is prevented 
by a friction brake on its shaft, and compensation for the varying 
diameter of the film on the take-up spool is obtained by means of a 
friction clutch driven by the motor through a vee-belt. A circular 
housing around the take-up spool has been devised to reduce the pos- 
sibility of flaying of the trailer end of the film. Both film spools are 
fastened to their respective spindles when the film is run through the 
camera, making it possible to operate the camera in any position. 



324 



. L. BOON 



Vol 43, No. 5 



This construction also prevents unwanted vibration from the loose fit 
of the spools on the spindles. 

All types of 16-mm film (up to 100-ft lengths) may be used in the 
camera although care must be taken to see that it is wound on alumi- 
num spools which do not have separable film clips on the core. By 
eliminating the timing-clock image from the main picture area, stand- 
ard 16-mm pictures are now recorded on the film. 

From our past experience, we have learned that it is difficult to 




FIG. 3. Side view of Eastman Type III High- 
Speed Camera, showing the motor and speed 
control rheostat. 



perform control operations during the run of the film through the 
camera a period of time which may be less than 2 or 3 sec. We, 
therefore, make use of a mechanically driven cut-off switch which, 
when pre-set for the length of film being run, automatically cuts off 
the current to the motor at the correct time, thereby decreasing the 
chance of damage to the camera from excessive acceleration. Ap- 
proximate picture-taking rate is controlled by pre-setting a rheostat 
limiting stop to the desired position (see Fig. 3). This rheostat also 
performs the function of bringing the camera up to speed by decreas- 



Xov., 1944 THE EASTMAN HIGH-SPEED CAMERA, TYPE III 325 

ing automatically the resistance in series with the motor up to the 
position of the limiting stop, which fixes the amount of resistance re- 
maining in series until the end of the run. 

A second switch operated by the camera motor, which has nothing 
to do with its electrical circuit, is incorporated in the camera and may 
be used to start the operation being photographed after any predeter- 
mined length of film has gone through the film gate. For instance, it 
may be desirable to fire a Photoflash lamp or trip a relay after .30 ft 
of film have run through the camera. This can be done without re- 
sorting to personal effort by plugging the second switch in series with 
the lamp or relay and its initiating current and setting the switch dial 
to the desired footage mark. 

To facilitate focus adjustments of the camera lens and to see the 
area being photographed, a telescopic magnifier has been built into 
the camera. The objective of this magnifier is slidable, and when in 
its forward position, high magnification is obtained for setting the fo- 
cus accurately; in its back position, the entire area being photo- 
graphed can be studied to determine the composition of the subject. 

Although the camera is equipped with an//2.7, 2 1 /2-in. focus lens, 
other lenses of the Kodak interchangeable-mount type (2-in. or 
greater focal length) can be adapted readily for use. The Kodak 
//1. 6, 2-in. lens, however, may be used only at near distances since it 
does not have sufficient back focus clearance. The standard camera 
lens is coated on all glass-air surfaces to increase the light transmis- 
sion and picture contrast. 

Subject lighting, except for self-luminous subjects, must be continu- 
ous during the run of the camera. Direct sunlight may be used at 
the slower speeds. Photoflood lamps and strong spotlights have been 
used with complete success for artificial illumination. Even Photo- 
flash lamps have been used where lighting is required for only a short 
time. Self-luminous subjects can be photographed readily, and Ko- 
dachrome pictures made of this class of subjects are particularly inter- 
esting. 

Owing to the shortage of some materials, changes have had to be 
made in order to manufacture these cameras, and in some instances 
manufacturers of purchased parts have also found it necessary to alter 
their products in a way not entirely satisfactory for our construction. 
In general, however, the original specifications for operation have 
been met in spite of the difficulties of manufacture under present con- 
ditions. 



326 J. L. BOON 

REFERENCES 

1 TUTTLE, F. E., AND REID, C. D. i "The Problem of Motion Picture Projec- 
tion from Continuously Moving Film," /. Soc. Mot. Pict. Eng., XX (Jan., 1933), 
p. 3. 

2 TUTTLE, F. E.: "A Non -Intermittent High-Speed 16-Mm Camera," /. Soc. 
Mot. Pict. Eng., XXI (Dec., 1933), p. 474. 



AN AAF PORTABLE SOUND RECORDING UNIT* 



F. T. DYKE ** 



Summary. This paper describes an extremely flexible portable sound recording 
unit assembled and placed in service by the First Motion Picture Unit of the Army 
Air Forces, whose Headquarters are located in Culver City, California. It includes 
a general description of the equipment used, with special attention given to the pro- 
vision of power supply facilities . 

The equipment selected is of such nature that special manufacturing processes are 
unnecessary, and power supply arrangements are such that use of the channel is not 
restricted by the fixed conditions of weight and bulk usually associated with the con- 
ventional recording channel. 

Sound recording, as practiced in motion picture studios today, is 
considered a field of endeavor which has passed the infancy stage. 
Equipments and techniques have become more or less standardized 
throughout the industry, owing to the efforts of the studios them- 
selves, and through the coordinated activities of such organizations 
as the Society of Motion Picture Engineers, the Academy of Motion 
Picture Arts and Sciences, the manufacturers, and others. The 
final product of all has become reasonably uniform only the methods 
of obtaining that product vary from one studio to another. 

With the activation of the Headquarters of the First Motion 
Picture Unit of the Army Air Forces, whose basic function is the 
production of training films for use by the Air Forces, the re- 
sponsibility has resolved upon those active in the sound section to 
obtain that same uniformity of product "GI" style. The nature 
of the work itself, together with matters of personnel and equipment 
available, has presented some unusual problems. It has been neces- 
sary to abandon the more conventional practices and resort to im- 
provisation and substitution to accomplish many of the varied mis- 
sions assigned. These missions vary widely in nature and scope. 
A recording channel with its operating crew may be called upon to 

* Presented Apr. 18, 1944, at the Technical Conference in New York. 
** First Lieutenant, First Motion Picture Unit, Army Air Forces, Culver City, 
Calif. 

327 



328 



F. T. DYKE 



Vol 43, No. 5 



record in rapid successive moves on a sound stage, with all its facili- 
ties, in an airplane, airborne or aground, in an airfield hangar, out 
on a remote part of a runway, in an aircraft factory, among a 
group of mobile repair or radio trucks from there to an operations 
tower, and then back to a sound stage for process shots. 

Transportation facilities vary widely. The channel may take a 
2-mile ride in a jeep, or a cross-country jaunt aboard a fast bomber, 




FIG. 1. 



or by slow freight. It must be prepared to operate strictly on its 
own or as a unit in a highly coordinated operation, such as is de- 
manded by process projection scenes. 

To fulfill such requirements, an extremely flexible sound recording 
channel has been assembled and placed in service at this Head- 
quarters as an all-purpose, portable unit, completely adaptable to 
whatever conditions may be encountered. The component parts 
were selected for immediate availability rather than for superior re- 
sults to be obtained, and they were assembled in such a manner so 
as not to be bound by any fixed condition; and most important, no 



Nov., 1944 AN AAF PORTABLE SOUND RECORDING UNIT 329 

specially manufactured equipment was necessary. The basic 
channel as it now stands consists of a mixer console capable of 
handling 3 microphones, an electronic mixer or volume compressor, 
a power amplifier, a ground noise reduction amplifier, and a variable- 
area galvanometer-type film recorder, together with the all-important 
power supply apparatus. (See Fig. 1.) 

The use of Western Electric Type 630 ("eight ball") microphones 
was decided upon for their uniform quality, ability to stand punish- 
ment, lightness, and relatively high output level. RCA Type MI- 
10209 microphone amplifiers are used ahead of the mixer console so 
that vulnerable low-level lines are avoided. The console, in addition 
to the microphone volume controls, provides a variable gain monitor- 
ing line and an adjustable high-speed volume indicator meter, each of 
which is bridged directly across the recording galvanometer, so that 
the mixer at all times monitors on the complete recording channel, a 
condition doubly necessary when a volume compressor is used. 
Western Electric Type 705 headphones are employed for high quality 
and dependability. The console also provides a signal-telephone 
line to the recorder, with an extension for an auxiliary telephone when 
necessary. 

The compressor, power amplifier, and ground noise-reduction 
amplifier are of the type manufactured by RCA and listed as part 
of the PM-40 Portable Recording Channel. These units are ar- 
ranged for either a-c or d-c operation. The compressor is mounted in 
one case, the remaining 2 units combined in a second case. They 
have been modified only to the extent needed to provide essential 
cabling and power facilities. The compressor has been provided 
with a "de-essing" equalizer, an addition found necessary for this 
type of recording. The gain frequency response of the channel is 
strictly conventional, in accordance with present studio practices. 

A standard RCA Type PR-22 film recorder is employed without 
modification. This recorder utilizes the rotary stabilizer to control 
film motion, a device found to be ideally suited for this type of work; 
the bilateral aperture and noise-reduction shutters; the ultraviolet 
filter; it is equipped with a footage counter and tachometer, and is 
arranged to operate with synchronous, Selsyn, or dc-ac interlock 
motors. The recorder is provided with a suitable carrying case con- 
taining a shock-proof mounting. 

Provision for power supply has been so arranged that when storage 
batteries must be used, a single set providing 36-v d-c is sufficient for 



330 F. T. DYK Voi 43, No. 5 

all purposes. Since any type of battery may be used, it is not neces- 
sary to carry them when weight and bulk are factors in transportation. 
The essential units may be secured at the destination. All component 
parts of the channel are interconnected by means of flexible, rubber- 
covered, shielded cables equipped, where necessary, with conventional 
Cannon plugs. The shields and grounds have been so arranged that 
the speech circuits are isolated from the motor circuits; therefore, 
pickup troubles originating in the motor lines are eliminated. 

When the channel is operated near a source of 110-v a-c supply, 
the compressor, power amplifier, and ground noise amplifier provide 
their own heater and plate voltages. A tap has been provided in the 
compressor plate supply circuit which furnishes plate voltage through 
the console to the microphone amplifiers. A source of d-c heater 
voltage is necessary for these amplifiers and is provided by means of 
cables with clips which may be connected to the storage battery when 
used, or to a low voltage rectifier. A rheostat and voltmeter are in- 
stalled in the console for metering the heater voltage. This A supply 
is also used to energize the telephone subsets in the console and at the 
recorder position, and illuminates a VI meter light. 

When a source of 1 10-v a-c supply is not available, a small, portable, 
Philco plate supply dynamotor is connected to provide plate voltage 
to all amplifiers. The dynamotor is driven from an 18-v tap across 
the common storage battery, and has a manually controlled voltage 
adjustment. One unique feature employed is the manner in which 
the plate voltage is supplied to the unit. This voltage is applied 
directly across the plate-heater circuit of the a-c rectifier tubes, so 
that the filters provided for a-c operation are used also for the plate 
generator. This arrangement permits immediate substitution of any 
suitable plate supply dynamotor, or a set of B batteries. 

A source of low voltage d-c supply is required for operation of the 
exciter lamp in the recorder, and for operation of the amplifier heaters 
when 110-v a-c is not available. The supply leads for this purpose 
are so arranged that they may be connected to the storage battery, 
or to a suitable low voltage rectifier, such as the RCA MI-3528 power 
supply. 

When it is desirable to use synchronous motors for driving cameras 
and recorder, and a source of 220-v, 60-cycle, 3-phase, a-c supply is 
available, the motors may be connected directly to the supply line 
through suitable switches furnished. When the supply is not avail- 
able, a Robin Stedypower portable a-c supply motor generator set is 



Nov., 1944 AN AAF PORTABLE SOUND RECORDING UNIT 



331 



utilized. This operates from the common storage battery, and has 
excellent frequency regulation. If it is necessary to use the re- 
corder as a part of a Selsyn interlock system, such as would be the 
case while recording with process projection equipment, a simple 
substitution of the recorder motor and cable is made, and the process 
distributor is used for interlock and driving motor power. 

When weight and bulk limitations impose restrictions, a dc-ac 
motor system is utilized, in this case the power is furnished by the 




FIG. 2. 



most readily available source, such as a set of dry batteries, or the 
output of the d-c generator which is usually carried with a produc- 
tion unit for set lighting purposes. 

No trouble has been encountered because of the method of furnish- 
ing low voltage d-c supply to the various components from a common 
storage battery, the grounding and shielding circuits having been so 
planned that objectionable disturbances can be easily eliminated. 
Supply leads from the battery are provided with clips, so that 
voltages may be adjusted in accordance with existing conditions, ancl 
a balanced discharge can be maintained. 



332 F. T. DYKE Vol 43, No. 5 

A battery charger is usually carried, and may be used to keep the 
batteries completely charged at all times, removing the necessity for 
night charging. Charging usually can be maintained while the 
channel is in use. On occasions, when 110-v a-c was not available, 
batteries have been floated, and even quick-charged by making use 
of the 110-v, d-c light generator, using the conventional set light 
dimmer to control the charge rate. Also, throughout the Air Forces, 
many types of portable generators are available which furnish ideal 
sources of 'power. 

Once the channel is set up, a minimum amount of time is required 
to prepare for recording. A small fixed frequency oscillator is pro- 
vided, so that it can be connected to the console in place of a micro- 
phone amplifier. The VI is equipped with a calibrated potenti- 
ometer so that accurate checks can be instantly made, such as the 
amounts of compression or noise-reduction margin used, level at 
which 100 per cent modulation occurs, etc. Provision is made for a 
monitor for the recordist, either by headphones or loudspeaker. 
Telephone communication between the mixer and recorder can be 
augmented by the use of a microphone installed at the console, 
whereby the mixer may give instructions to the recordist, using the 
channel amplifiers and monitor system. 

Hence, it should be readily seen that once the nature of an assign- 
ment is known, the channel may be quickly prepared for it, and only 
the requisite amount of apparatus need be taken. A GI truck, with 
the ability to move itself over any terrain, is usually provided for 
transportation. But the channel may be stripped down and easily 
carried in a "jeep," an airplane, a small boat, or by rail. (See Fig. 2.) 

Thus, we have provided, without resort to special equipment or 
manufacturing processes, a complete, all-purpose recording channel, 
capable of producing entirely satisfactory results under all probable 
conditions that may be encountered in the production of sound 
motion pictures for use in the training of personnel in the Army Air 
Forces. 

The accompanying schedule will illustrate more clearly how the 
wiring has been arranged to utilize the various available sources of 
power supply : 

Unit Power Supply Provision 

f Any source of 8-v, A supply. 
Preamplifiers and Oscillator I * . 

. i An 8-v tap from the common storage batterv. 

(Heaters) . .. -, , 

(A suitable low voltage rectifier. 



Nov., 1944 AN AAF PORTABLE SOUND RECORDING UNIT 



333 



Volume Compressor (Heaters) 
Power Amplifier 
GNR Amplifier 

Volume Compressor (Plates) 
Power Amplifier 
GNR Amplifier 



Recorder (Exciter Lamp) 

Motors (Synchronous) 

Motors (Interlock) 
Motors (DC-AC) 
Telephones 
Battery Charging 



Unit Power Supply Provision 

Any source of 110-v, a-c supply. 
Preamplifiers and Oscillator A suitable dynamotor. 
(Plates) B batteries. 

A suitable plate rectifier. 

Any source of 110-v, a-c supply. 

Any source of 6-v, A supply. 

A 6-v tap from the common storage battery. 

A suitable low voltage rectifier. 

Any source of 110-v, a-c supply. 

A suitable dynamotor. 

B batteries. 

A suitable plate rectifier. 

(Any source of 18-v, A supply. 

\ An 18-v tap from the common storage battery 

[A suitable low voltage rectifier. 

[Any source of 60-cycle, 220-v, 3-phase supply. 
JThe M-G set driven from the common storage 
battery. 

j Any Selsyn or interlock motor and distributor 
\ system. 

j Any source of 110-v, d-c supply. 
(B batteries. 

Any small 6-v. dry battery. 

An 8-v tap from the common storage battery. 

Any suitable battery charger. 
Any suitable source of d-c supply. 



THE TRAINING FILM FORMULA* 
ORVILLE GOLDNER** 

Summary. To carry on an extensive training film program it is necessary to 
define terms and procedures in order to eliminate confusion and cut to a minimum 
the many aspects of the job which are generally considered as unpredictable. 

Five factors must be considered in the construction of every training film: the truth 
about a condition or set of conditions, interpretation of the truth, visualization, ver- 
balization, and emphases. These 5 factors make up the basic training film formula, 
variations in the application of which result in the pattern of the film. The pattern 
of any training film is as interesting and effective as the mental, manual, and mechan- 
ical skills and equipment used in the development of the formula permit it to be. 
The pattern of a given training film is established for the purpose of achieving specific 
predetermined objectives with a specific audience. 

The business, i. e., production, distribution, and utilization of train- 
ing films, as carried on by the Armed Forces, is no longer a fringe ac- 
tivity without status and influence. Its importance in the war effort 
is being proved repeatedly at shore stations, advance bases, and in 
the fleet. Service personnel almost everywhere now have some 
contact with training films. 

The motion picture has made its mark in a new field on a large scale 
it has moved from the corner theater to the Quonset hut, the 
hangar deck, and the ward room. Chameleon-like it has taken on a 
new aspect changed its gaudy colors for entertainment to mellow 
tones for training, and the tradition, the force, the holding power of 
the motion picture have moved into these new spaces easily because 
movie-mindedness comes easily, as air-mindedness does. When space 
and time merge as they have today it is as easy and natural to expect 
motion pictures in Iceland and Bougainville as it is to expect Flying 
Forts and Liberators. 

As the training film business grows and matures, it is necessary to 
look at the job being done to check the specifications, the parts, the 

* Prepared for the Technical Conference in New York, Apr. 18, 1944, but not 
presented. 

** Lieutenant Commander, USNR, Head, Training Film Branch, Bureau of 
Aeronautics, U. S. Navy, Washington, D. C. 
334 



THE TRAINING FILM FORMULA 335 

designs, the purposes, to look at the job not from the volume point of 
view and the maze of mathematics which indicate man-hours, miles 
of film, and millions of dollars, but from the unit point of view at 
that significant item the training film itself. It is necessary now to 
check the terms, to eliminate the confusion in fact, to dissolve 
the mystery and the unpredictability which characterize the motion 
picture business as a whole. 

At this stage of the training film job with thousands of effective 
and ineffective specimens at hand, it makes good sense to analyze as 
scientifically as possible that ephemeral screen experience for training 
to see "what makes it click." Only by dissection, analysis, and defi- 
nition can we hope to get closer to understanding and creating the 
special film that is to be the sharp and dependable tool for training. 

Upon analysis we find that the agglomeration of sight and sound 
experience which reaches and emanates from the screen is not some- 
thing formless and indescribable certainly not esoteric. Whether 
it is a theatrical motion picture or a training film it is the result of skills 
and developments which for purposes of clarity we shall refer to as 
"ingredients." 

Inasmuch as we are concerned here specifically with the training 
film, we shall separate these ingredients and determine the formula 
of the training film, and how the formula is varied to give us the 
pattern, that is, the total style of presentation. And formula and 
pattern will be kept separate, for one is the means and one the end. 
The pattern must not be confused with the formula because the 
pattern is a result of a use of the formula, the important points 
being: first, that this resulting pattern may be either singular 
and completely effective or prosaic, and partially effective when 
evaluated for a predetermined objective; and second, that different 
patterns can result from a use of the training film formula even when 
the objective remains the same. 

Now, perhaps there are some who wonder why it is necessary to go 
to all the trouble of analyzing and defining the structure of training 
films when it is so much easier to shoot pictures from an outline or 
"off the cuff" and then cut and recut, write and rewrite, until you 
get what you want, or should we say a fair compromise with what 
you want? It may be easier to make "films" this way and it may 
be more fun. However, just "films" are not training films, and rolls 
of celluloid covered with uncorrelated photographic images and 
meaningless words and sounds seldom meet a training need. Fur- 



336 O. GOLDNER Vol 43, No. 5 

ther, you cannot carry on an extensive training film production pro- 
gram by using such haphazard, hit-or-miss methods. To qualify 
this statement a little, let it be said that you can carry on an ex- 
tensive training film production program along such lines, but not 
when time, money, and maximum effectiveness must be considered 
at all times. This is the position of the Training Film Branch of 
the Navy and this is sufficient justification for analyzing the training 
film, for separating the predictable elements from the unpredictable, 
and for studying the mental, manual, and mechanical aspects of 
the training film production job. 

To get an understanding of the difference between the training film 
formula and the pattern the resulting style and meaning in total it 
is logical to resort to an analogy. 

Let us take a mural as an example, the type of mural we find in 
many post offices the one which portrays the history of the United 
States Mail System from the days of the Pony Express to modern 
air mail. When such a mural is viewed by the thousands of persons 
who come in contact with it, it means not only many different things, 
but it means these things with greatly varying degrees of intensity. 
Many of the individual meanings may be quite different from those 
the artist had in mind when he painted the mural. Some persons 
may read into the mural all kinds of meanings that ai e subsidiary to 
the main historical story which the mural is designed to tell. Others 
may read into the mural "extra" meanings which are so important 
as to make the main theme itself effectless as far as they are concerned. 
There will be some who will find in the mural very personal meanings 
and much that is sentimental. Still others will find it only "interest- 
ing" or meaningless. Inevitably, there will be a few who will enjoy 
the mural for what it is a fine art form, a use of skill and imagination 
expressed in oil paint on canvas. The enjoyment and meanings for 
this group will be clinical. This group will be far more interested in 
what the mural is intrinsically than what it attempts to say and mean 
extrinsically. 

So our mural will mean a thousand things to a thousand individuals. 
Its importance as an effective contributing experience in American 
history will depend on many factors. Most of all it will depend on the 
commonness of the forms, i. e., the signs and symbols, which are 
used to interpret the theme the story of the U. S. Mail System. 
And the commonness of the forms depends entirely on what the audi- 
ence brings to the mural in the way of mental and emotional experi- 






Nov., 1944 THE TRAINING FILM FORMULA 337 

ence and educational background. In other words, there will be 
much or little meaning in direct proportion to the commonness of the 
elements of the mural to the existing and potential life history of the 
total audience, which in turn depends on the age, the heritage, the 
environment, the education, the vocations and avocations, the 
habits, desires, and ambitions of every individual. 

We can then conclude that to give the most meaning to the visuali- 
zation of any subject matter it is necessary to ascertain as completely 
as possible the common denominators of the total life experience of the 
audience for whom we are "visualizing." 

From this analogy we see quite clearly that the pattern of the 
mural and the resulting meanings in their little or great importance 
and varying intensities depend on the artist's ability to talk the 
language of his audience using only visual signs and symbols. This 
indicates unequivocally that he must know a lot about his audience 
their education, their experience, and their habits and attitudes. 
More, he has to know how they express themselves and how they 
learn that is, what visual forms and qualities in a context of new 
experience have meaning for them. 

It is evident that we can translate directly the requirements of the 
mural painter to the instructional film maker. But the film maker 
has one more problem. He has to understand the values of audible 
forms, the spoken language and sound, when they are used with 
pictures. He has to synthesize carefully, adding just the right kinds 
and amounts of words and sounds to pictures to guarantee more 
meaning and more learning. And always, this job, too, must be 
done in the terms of a given audience. If the film maker does not 
understand the importance of a harmonious marriage between pic- 
tures and sound for a purpose, for an audience, only one thing can 
result a panorama of innocuous visual images accompanied by a 
cacophony of sound, an experience which may keep an audience awake 
but which will be quite without lasting meaning and learning. 

It should now be clear that the product of the film maker's art and 
craft that experience ^which reaches the screen is a cohesive force, a 
delicate synthesis of design and technique, a total pattern that may be 
coherent or incoherent, meaningful or meaningless, .with or without 
quality which can be described or evaluated only as it affects an 
audience. 

To illustrate further the difference between the formula of a train- 
ing film and its pattern, and how many individual patterns will result 



338 O. GOLDNER Vol 43, No. 5 

from a use of the same formula, let us return again to the analogy of 
the historical mural. Let us assume that we have a post office in a 
town in the Middle West for which we want such a mural painted. 
We offer the job of painting on a competitive basis. Five artists are 
given complete specifications for the project. They are given all the 
exact dimensions of the space into which the mural is to fit, the 
quality of the canvas and paint that is to be used, a time for comple- 
tion of the work and a color scheme, or at least a definite indication 
of the colors of floors, walls and ceiling with which the mural must 
harmonize. In addition, they are furnished with a detailed story of 
the theme. 

The 5 artists on receipt of the mural's specifications begin word and 
picture research. It is entirely possible that they will use the same 
source materials. But at this stage something happens. Each artist 
draws from the source materials the parts which seem cogent to him 
and he begins his plans and sketches. The picture and word facts 
which he gathers are segregated, expanded and combined, over and 
over again until he achieves a satisfying totality a complete visuali- 
zation of a group of ideas which pleases him aesthetically. When he 
has achieved what is to him a balance between fact and imagination 
expressed graphically, he is ready for paint, brushes, and canvas. 
The important point here is that each of the 5 artists will arrive at 
a different balance between fact and imagination, and each will ex- 
press his graphic totality in a different style and different colors 
yet all 5 artists will be fulfilling the requirements of the mural 
competition. However, each artist's work, if completed for the 
given audience passing through the post office of the middle western 
town, will have a different effect that is to say, will mean to the 
audience different things with different intensities. These meanings 
and their effects in total may be described by the audience in empty 
sentences without qualifications, such as "I like it"- -"It's beauti- 
ful" "I don't understand it," etc., but of one thing we can be sure: 
one of the murals will mean more and mean it. more effectively than 
all the rest. 

Our conclusion must be that: The same specification, research 
data, tools, equipment, and material used in the development of a 
given "theme" for a specified objective result in greatly different end 
products because of 2 factors the quality of the craftsmanship 
expressed in the use of tools, equipment, and materials, and the 
appropriateness of the imagination applied to the interpretation of 



Nov., 1944 THE TRAINING FILM FORMULA 339 

research data which we assume to be the truth. And a training 
film, like a mural, is the result of basic factors or "ingredients," the 
accumulation of which we shall refer to as the formula, and the 
imaginative result of which we shall refer to as the pattern. Further, 
a training film formula like any other has to be exact and dependable 
and made up proportionately to accomplish definite predetermined 
results. 

A qualitative analysis of any training film reveals the following 
ingredients in the order of their application in the training film pro- 
duction process: 

(/) The truth about a condition or set of conditions. 

(2) Interpretation of the truth as it relates to human behavior. 

(3) Visualization of the interpretation of the truth in a way that will permit 
individual identification with it. 

(4) Verbalization of the interpretation of the truth in terms and in a manner 
that will permit the relatively effortless development of definite behavioral 
concepts. 

(5) Emphases, both visual and audible, which emanate naturally out of the 
interpretation of the truth (2, 3, 4 above), and which will add to the immediate 
and retentive value of the whole. 

For a better understanding of the 5 ingredients of the training film 
formula, we shall examine the details of each to determine its char- 
acteristics and the skills required for its accomplishment. 

(1) The Truth about a Condition or Set of Conditions. Obviously, 
this is the first thing- to be determined in the production of a training 
film. The truth about any subject can be learned only after all the 
available sources of information have been tapped. To get at the 
truth about a condition or set of conditions as the basis for a training 
film, it may be necessary to do a number of different things 

(a) Read books, manuals, reports; 

(6) Visit locations where the subject matter may be studied in fact and in 
operation (as opposed to its presentation in writing and conversation) ; 

(c) Conduct interviews with persons having an operational knowledge of the 
subject matter; 

(d) See motion pictures on the same, similar, and allied subject matter. 

The nature of the job of determining the truth indicates plainly 
that it requires a person who knows how to "search out" and appraise 
existing information on the given subject matter. It requires a 
person who is not satisfied with surface observation and the easily 
accessible, but rather one who has the ability to penetrate the com- 
mon and accepted facts and alleged facts. Frequently, in Navy 



340 O. GOLDNER Vol 43, No. 5 

work the job of determining the truth for a training film is difficult 
more difficult than might be expected because weapons, in the sense 
that machine guns and battleships are weapons, tactics and per- 
sonnel change almost from day to day. This means that doctrine 
changes rapidly, and that what was true yesterday entirely or in 
part may not be true today. This means, also, that as the history of 
a training film is written, over one-third of the time it is in production 
is entered against "research." 

Whatever the difficulties of establishing the truth, it is the first 
important step in the production of a training film, and if the truth 
is literally in transition, it must be "frozen" as of a given moment in 
preparation for the next step. A knowledge of training film methods 
is not necessary for the work of this first step, but mental acuity 
and 'a knowledge of research techniques are a positive requirement. 

(2) Interpretation of the Truth as It Relates to Human Behavior. 
In the process of interpreting the truth as it relates to human be- 
havior, there is implied at once a given audience because human be- 
havior is different at different ages, and it is dependent on many fac- 
tors including the education, experience, heritage, and environment 
of the individuals making up the audience. In practice, interpreta- 
tion of the truth for a Navy training film amounts to a precise but 
complete statement of the film's content based on results of the 
initial research (the truth). The content is delimited, that is, only 
such segments of the truth are set down for inclusion in the film that 
are considered important for influencing the behavior of the defined 
audience. The business of interpreting the truth, and delimiting to 
establish the required segments for an audience demands a thorough 
knowledge of the objective of the film and the relationship the film 
will have to a curriculum if it exists. If no curriculum exists and the 
film is to "stand on its own feet" and be a complete meaningful ex- 
perience without supplementary assistance, a different interpretation 
of the truth will have to be made. In all probability the interpreta- 
tion will have to be more general with some attention given to intro- 
ducing and summarizing the subject matter. There is a wide variety 
of unique circumstances and audiences, each of which requires a spe- 
cial interpretation of the truth. In this second step of training film 
production such special requirements are determined. In this, step, 
though not in the first, a knowledge of the construction of training 
films is essential. 

(3) Visualization of the Interpretation of the Truth. This in- 



Nov., 1944 THE TRAINING FILM FORMULA 341 

gradient of the training film formula demands "picture mindedness." 
To accomplish a complete and forceful visualization of the segments 
of the truth resulting from its interpretation and delimitation, it is 
necessary to "see" in detail the totality that is to become the screen 
experience the training film. This process of seeing "in the mind's 
eye" all of the correlated details and their interrelationships must be 
translated into words in a script which can be read and understood by 
a cameraman, any cameraman in fact, by anyone concerned in pro- 
duction whether he is conversant or not conversant with the subject 
matter. 

For the visualization of complex material in a script it is often 
necessary to use drawings and photographs. This is a sure procedure 
when words alone will not make graphic the obscurities of abstract 
problems, e. g., Location of Points on the Celestial Sphere (celestial 
navigation), The Occluded Front (weather), The Chain of Asepsis 
(surgery). Regardless of the method used to visualize the inter- 
pretation of the truth in the script, it must contribute to the pro- 
duction of moving pictures which will permit the individual student 
to identify himself closely with whatever he sees. For he must 
"feel" the visual experience as a mental-emotional entity. There 
must be an experiential bond, a ^anesthetic response to the actions 
pictured. Vicariously he must get as close to actual experience in a 
specific area as is possible. Only if he does, is the visualization of the 
interpretation of the truth, the pertinent delimitation, adequate and 
effective for learning. This step in the production of a training 
film requires (1) the mental and manual skills of writers and artists 
who can put in a script whatever will assist production technicians 
in getting to the screen the right "moving pictures;" and (2) the men- 
tal and manual skills of technicians who, with equipment and ma- 
terials, can translate the adequately visualized scripts into specified 
quality "moving pictures." Cameramen, animators, carpenters, 
scene painters, laboratory technicians, and many others, including 
actors, are a part of this job. So this step in training film production 
depends on 3 factors, mental, manual, and mechanical for its accom- 
plishment. Visualization is the third and, by all measurements, the 
most important ingredient in the training film formula. 

(4) Verbalization of the Interpretation of the Truth. Verbaliza- 
tion as it applies to training films means, simply, the use of words with 
pictures to explain, interpret, and extend their meanings. However, 
because words come easily and may be changed and shifted easily, 



342 O. GOLDNER Vol 43, No. 5 

there is always prevalent the danger of putting into words what 
should be in*pictures. This fact accounts for training films that are 
packed with words like cars on a busy street one against the other 
until none stands out, until any one is like all the rest. 

Three conditions are important in the use of words in training 
films: 

(1) The vocabulary must be "geared" to the audience. The words used 
must not be "over their heads," or have a "talk-down" effect. 

(2} Words should be used only where absolutely necessary to an understand- 
ing of the picture. Words should not be used for themselves alone. 

(3) Voices and voice quality used for narration must give the impression of 
understanding the subject matter. They must be "voices of experience" talking 
personally to and not impersonally at the audience. There must be no "selling" 
but rather sincere and straightforward "informing." 

As has been stated, the interpretation of the truth should be ver- 
balized in a manner that will permit the relatively effortless develop- 
ment of definite behavioral concepts. In other words, the audience 
should not be conscious of 3 experiences seeing, hearing, and 
understanding, or attempting to understand. If words fit pictures 
and both fit the audience, the whole training film experience will be 
effortless and without fatigue, and effective learning will take place 
painlessly. If words fit pictures and both fit the audience, the 
development of behavioral concepts will be orderly and natural, and 
understanding expressed in action will be inevitable. 

For this step in training film production there are required (1) the 
skills of "seeing" writers, picture -minded writers, who know that 
what is seen of "Fourth-of-July" fireworks is more important and 
lasting than what is heard; and (2) voices and technical equipment 
that can put on training films the words which, when released with 
specific moving pictures, are easily understood and pregnant with 
meanings. 

(5) Emphases Visual and Audible. This last ingredient in the 
training film formula is by far the most difficult to explain because it 
covers many techniques the gamut of optical effects and screen de- 
vices, music and congruous sound, and many others. All of these 
are used in training films, sometimes well, often badly, but always, 
purportedly, to increase the effectiveness of the films. And yet how 
many training films have been unpleasant and irritating experiences 
because they were full of senseless "opticals," so-called humor in 
picture and sound, loud ill-fitting music, and other "effects?" 

On this ingredient of the training film formula, Emphases, the im- 



Nov., 1944 THE TRAINING FILM FORMULA 343 

portant point is that they must "emanate naturally out of the inter- 
pretation of the truth and add to the immediate and retentive 
value of the whole." The fade-in and -out, lap dissolve, wipe, mon- 
tage, double exposure, and the wide variety of other screen devices, 
all may serve useful purposes in the training film. So, too, may 
music and humor, but only if they add in some direct and natural 
way to the assimilation and retention of the subject matter being 
presented. It must be admitted that many of the values of these de- 
vices though accepted as genuine and important are yet unproved. 
It is safe to conclude that straight cuts and restrained use of other 
effects will add up to better training films if the jobs of visualization 
and verbalization are done with incisiveness to interpret delimited 
truths for given audiences. 

The fifth ingredient of the training film formula and its devious 
techniques requires many skills and much equipment. It requires 
the special and peculiar training of technicians ranging from cutters 
to musicians and sound-effects men. Whatever it requires in the 
way of mental, manual, and mechanical skill and equipment, it re- 
quires most of all a profound and discriminating sense of combining, 
synthesizing, on a continuous piece of film many pictures and words 
for an experience which will contribute in a tangible way to learning. 

These, then, are the 5 ingredients of the training film formula, 
the imaginative and creative use of which results in the training film 
pattern. The ingredients of the formula are for the most part pre- 
dictable to the extent that (1) the known truth about any subject 
can be determined at a given time; (2) the truth can be interpreted 
and delimited for given objectives for a given audience ; (3) the inter- 
pretation of the truth can be visualized; (4) it can be presented in 
words; and (5) all this can be combined and blended with a variety 
of emphases for definite purposes. And the mental and manual 
skills, the equipment, and materials used in the development of the 
ingredients are reasonably predictable. 

To summarize, training films that are predictable as to effectiveness 
are scientifically constructed when all of these factors are understood 
and used creatively for their full potential. It is hoped that by pre- 
senting the training film formula in positive terms, a fresh approach 
can 'be made to the separation of "predictables" from "unpredict- 
ables" in training film construction, and further that by imaginative 
thinking about the ingredients of the training film formula, more 
interesting and effective training film patterns will result. 



THE TRAINING FILM AN INSTRUMENT FOR 
THE CONTROL OF HUMAN BEHAVIOR* 

HAROLD B. ROBERTS** 



Summary. The producer of training films may well combine the discoveries of 
psychology with the techniques of the motion picture. Such a combination will have 
as its antecedent the realization that a training film is only as good as it is an effective 
instrument of behavior control. While changes in the behavior of the trainee provide 
the final measure of excellence of the picture, standards of excellence must be con- 
sidered before and during production. A film to be effective must 'have 4 basic 
characteristics: it must be built in the form of a narrative, around the successful solu- 
tion of a problem; it must possess opportunities for directed identification; it must 
oe convincingly logical; and it must be an artistic production. 

Training is a process by which a relation is established between 
human behavior and a given problem. Ordinarily, training is the 
process by which the behavior of man is established in relation to a 
social situation or to something man has created. The objectives 
of training must always be stated in terms of accomplishment, of 
effective individual action in the solution of a problem. 

Training in the Navy is the process by which the behavior of 
Naval personnel is changed from behavior- which has been effective 
in civilian life to that which will be most effective in the handling of 
Naval equipment and personnel in combat and combat support. 
All Navy training points toward the successful operation of the 
fleet. Some personnel are attached to the fleet, others may be 
hundreds of miles from any sign of a fleet. But the fleet is the focus 
of their activity. 

The success of the fleet depends upon the behavior of large num- 
bers of Naval personnel in relation to each other and in relation to 
the technical equipment of the Navy. The problem of training is 
control of that behavior. 

Success in training is in direct proportion to the predictability of 
behavior. The individual is said to be trained when his behavior in 

* Presented Apr. 18, 1944, at the Technical Conference in New York. 
** Lieutenant, USNR, Training Film Branch, Bureau of Aeronautics, U. S. 
Navy, Washington, D. C. 

344 



THE TRAINING FILM 345 

relation to his job is predictable beyond a reasonable doubt. A 
machine gunner is trained when he can assemble and disassemble his 
gun, when he can load it and fire it, and when one can safely predict 
that he will do all of these things in the right way at the right time. 
His total training involves a great many more types of behavior, but 
in relation to his gun, the predictability of his behavior is the measure 
of the success of his training. 

Strange as it may seem, the behavior which the individual exhibits 
toward a piece of equipment (or toward personnel, for that matter) 
may or may not be directly related to his knowledge of it. The ma- 
chine gunner may have a thorough knowledge of the 20-mm machine 
gun. He may know its weight and the weight 9f the projectile, the 
names of the parts of the gun, the amount of the powder in the shell, 
and the mnzzle velocity of the projectile. But if he cannot dis- 
assemble the gun and assemble it under the worst conditions, even 
though he knows the purposes of the parts, if his shooting is medi- 
ocre, even though he knows and can explain proper form in shooting, 
the contribution which he will make is open to question. 

Knowledge cannot be substituted for behavior as a satisfactory 
measure of success in training. In general education, we may give 
examinations and measure success by examination grades, we may 
teach facts and assume behavior, or teach concepts and assume the 
solution of problems by these concepts. But these are grim days, 
and inadequate training means the difference between life and death 
and battles lost or won. The behavior of officers and men in rela- 
tion to each other and to mateViel will prove a deciding factor in the 
outcome of the war. 

The training officer who settles for anything less than predictable 
behavior misunderstands his assignment, and so does the training 
film maker who proceeds on the assumption that the imparting of 
knowledge is a sufficient aim of a training film. 

The training film must be produced on the assumption that it will 
change the behavior of the trainee. The training film is a training 
instrument, and it has the same type of responsibility as the training 
officer. It must influence and control behavior. It must also provide 
information. But more importantly, it must point out the problem, 
the solution of the problem; it must provide the trainee with the 
kinesthetic concept of the behavior and provide the motivation for 
action. The training film must provide the information on which 
to act, the knowledge of how and when to act. From it the trainee 



346 H. B. ROBERTS Vol 43, No. 5 

must gain a concept of the feeling of the action and the desire to act 
in the right way at the right time. 

The training film maker has the responsibility for seeing that 
these factors are a part of the training film. If the film cannot provide 
the trainee with behavior patterns, either the film is not a training 
film, or the behavior patterns must be provided from another source. 
The film maker must make certain that the behavior patterns which 
are not a part of the film, are provided elsewhere in the program of 
the trainee. 

Similarly if motivation has no part, or if information is not to be 
presented in a particular film, then the training film maker must 
know that they do appear elsewhere in the training program. 

Usually the training film is an instrument for the control of overt 
visible behavior and as such must include basically psychological 
factors which cover a large area and are too numerous to be covered 
in a single, paper. Four, however, I shall consider and briefly 
discuss : 

(1) A great many years ago, in 1575, there appeared in print a 
short English comedy in verse. The title of the yarn was "Gammer 
Gurton's Needle." It was not very good verse, or at least it was not 
very interesting verse, but some historians in the field of English 
literature hold it in esteem because it possesses certain character- 
istics which have been used in the modern short story, making it the 
most popular form of fiction in the last 4 decades. It may be said 
to constitute a discovery in the field of psychology. The author re- 
vealed, perhaps unconsciously, that human beings react most favor- 
ably to a new situation when it is presented in 4 or 5 parts. Experts 
have named these parts the introduction, the rising action, the 
climax, the falling action, and the conclusion. 

These parts appear also in the novel and the drama. In some in- 
stances they are in the order in which they appear here; in many 
instances that order is disregarded. A narrative may begin with the 
climax rather than the introduction and may end with almost any 
of the parts. Any part may be abbreviated or extended as the 
situation demands. 

It is the contention here that the best training films to date follow 
the structure of the novel, the short story, or the drama. There are 
several reasons why training films so constructed should prove most 
effective. In the first place, there is opportunity for the presentation 
of the problem to be solved. Actually all stories are the presenta- 



Nov./i944 THE TRAINING FILM 347 

tion of a problem. In most problems man struggles with man, or 
with nature, or with machinery, or institutions which he created. In 
a story, the introduction provides the opportunity for the presenta- 
tion of the forces, telling who and what are involved, and the place as 
well as the time. The rising action points up the problem, explains 
how the forces are related, and depicts the behavior of the character 
struggling toward the solution of the problem. The climax de- 
scribes the convergent action of all factors involved in the successful 
solution. The falling action and conclusion portray the effects, 
tragic or successful, of the action on the whole problem. 

The second advantage of the story form is the fact that of all the 
organizations of material for learning, the narrative structure is uni- 
versally the most interesting. Learning is painful at best. 'Under 
conditions in which there is fear or mental conflict owing to new 
situations or to danger, learning may approach the impossible. In 
any situation there is no rule against making learning as interesting 
as possible. The old law, which held that the more unpleasant the 
learning process the better the result, was disproved long ago even 
though the announcement may not have reached all alleged teachers. 

The narrative, in the third place, gives maximum opportunity 
for the presentation of a problem in terms of overt behavior. 

The narrative is peculiarly suited to the portrayal of activity. 
Stories can be written portraying man's internal struggle. It is 
possible to write a drama of mental conflict. But a story of mental 
operations requires the greatest finesse in comparison with one in 
which physical action predominates. The framework of the story 
lends itself particularly to the portrayal of overt behavior, which is 
the problem of training. 

The use of the story form is not free from danger. The training 
film maker who says, "Let us make a story out of it" should say 
"Let us find the story in it." The training film maker who adds 
characters to add interest is in danger of adding new and unrelated 
problems. A simple problem deserves a simple story. The simple 
story will hold interest when the length of the film and the com- 
plexity of the solution of the problem are commensurate with the com- 
plexity of the problem. 

The series of pictures on shipbuilding skills presents a new high in 
training film excellence. That series portrays a group of problems 
involving comparatively simple technical achievement. The char- 
acters are limited to man and his machine. The plots are simple. 



348 H. B. ROBERTS Vol 43', No. 5 

Man sees a job to be done, he selects the tools with which to do the 
job, he does it. The presentations are direct and concise. Interest 
is held throughout because the men responsible for the series found a 
simple story in each problem and presented it directly in a simple 
way. 

(2) The best training films to date appear to give the greatest op- 
portunity for directed identification. 

The motion picture producer is an expert in the field of identifica- 
tion. He knows that the success of his production depends upon 
the universality of the identification of the audience. He knows 
also that identification is not only relating the picture to the ex- 
perience of the audience, but also the relating of the self of each in- 
dividu-al in the audience to the individual characters. 

With the acceptance of the thesis that control of behavior is the 
aim of the training film, the importance of both phases of identifica- 
tion cannot be minimized. The first phase is inherent in the phrase, 
the trainee must be taken from the known to the unknown. The 
second is the process by which the trainee gains the behavioral con- 
cept and pattern. 

The ordinary movie audience identifies itself with screen behavior 
for the escape it offers, the trainee for quite a different reason. The 
trainee must in effect experience the behavior so that with the mini- 
mum of practice he can repeat it. The trainee not only must fit the 
situation to his past experience, but he may and indeed he must 
move with the characters through their behavior with sufficient 
identity to have introduced the basis for habitual action. 

A sequence from a picture on the assembly of a marine engine will 
illustrate. A mechanic is securing one part of the engine to another 
with a bolt. In close-up the mechanic starts the bolt with his hands. 
One sees the hands manipulate the bolt and perceives the amount 
of pressure applied by noting the strain on the fingers. When the 
fingers meet with sufficient resistance the mechanic reaches for a 
wrench. One sees the hands manipulate the wrench into position to 
continue with the tightening. By watching the hands, the arms, the 
back, and the expression on the face of the mechanic, a trainee ex- 
periences the muscular feel of the process. When the strain tells the 
mechanic (and the audience) that the bolt is tight enough, the 
mechanic moves to another part of the job leaving the audience with 
the picture, the sound, and the feel of the procedure. 

The extent or quality of identification provided is subject to 



Nov., 1944 THE TRAINING FILM 349 

restriction. Smooth, easy, expert behavior presented in a logical way 
may provide opportunity for identification. The film that portrays 
casual competence in a skill, that portrays subcortical behavior re- 
sulting from a deeply entrenched habit may encourage identifica- 
tion. Such behavior is indeed an excellent setting for identification 
for escape, and therein lies the danger. Realizing this danger, in 
the film on the disassembly of the torpedo stabilizer, the camera pans 
between the expert and the novice. The expert is showing the 
method, the novice the reason. In a film on combat action 4 fliers 
show us the right technique, while two show us the wrong. One of 
the two loses his life. Both pictures provide directed identification, 
but preclude the possibility of identification for escape. 

A common error lies in the elaboration of characters. One film 
involves one of the most dramatic problems of wartime communica- 
tion. The obvious characters were man and his equipment. 

The setting for identification was good. But the writer added a 
new character in the form of a teacher. The resulting cast included 
a teacher, 2 pupils, and the equipment. The teacher lectured for the 
most part; the pupils' behavior was limited principally to listening. 
In other words, the teacher identified himself with the equipment; 
the pupils identified themselves with the problem through the teach- 
er's words. The audience was left with a complex situation and to its 
own devices. Extraneous characters with interesting but unim- 
portant functions may serve only to upset the direction of the identi- 
fication. The identification must prevail along the lines and in the 
direction in which the change of behavior is expected. 

(3) The best training films to date are convincingly logical. A 
procedure that is expected to produce a behavior pattern must be 
developed in logical order. Possibly the commonest logical order is 
chronological. The assembly and disassembly of machinery are por- 
trayed in such order for the most part. In technical training, chrono- 
logical procedure predominates. But whenever a film says in 
effect, "Let us go back and check up," a new element of logic is in- 
troduced. Chronological order not sufficing, the training film maker 
has resorted to presentation in psychological order. The chrono- 
logical order serves the machine, the psychological the man. 

In the film on how an officer should report to a new station, the 
young Ensign sends his personal gear aboard ship in a small trunk. 
His gear properly stowed, he goes through the accepted chrono- 
logical series of steps in the completion of reporting. Near the end 



350 H. B. ROBERTS Vol 43, No. 5 

he glances through the porthole to see his trunk floating in the bay. 
He recalls that he was instructed to forward his gear in a wooden box 
that could be destroyed, because of the lack of stowage space. The 
script writer could have had the Ensign come aboard with the box in 
the first place, but he chose well to use this psychological device of 
delayed action in one short scene to impress the trainee with the logic 
of the entire picture. 

Man may control a machine in a defined chronological order' and 
there may be chronological steps in the assembly and disassembly of 
that machine. But man learns in whole patterns. Man does not 
learn in chronological steps. Man learns by grouping steps into a 
comprehensible whole. In the training film which portrays the dis- 
assembly of a small marine engine, a mechanic is seen removing the 
bolts that secure the engine head. He takes out one after the other 
in a logical numerical sequence. Following the removal of the final 
bolt, the engine head is lifted. At that point the trainee is im- 
pressed with the logic of the procedure, and he combines all the steps 
into a pattern. He has gained the pattern for the removal of the 
engine head. 

The procedure in the removal of the engine head has a natural con- 
vincing consequence. But a chronological procedure may have no 
evident consequence. In such cases one or more must be discovered 
if learning is to occur. A film without such psychological checks is 
particularly ineffective. 

One film portrays the duties of a petty officer in preparation for the 
starting of a steam turbine. He is to open or close approximately 
15 steam, water, and oil valves. These valves are distributed at 
uneven intervals around 4 of the 6 walls of an L-shaped room. The 
petty officer proceeds around the room opening or closing the valves 
in order of their occurrence. At the close of the series the audience 
can see that the petty officer believes the assignment to be complete. 
But the audience is without conviction. The trainee has been given 
no consequences of the activities of the character around which he 
can unify the preceding steps. In short, the trainee has not learned 
the procedure and he cannot learn it from the film alone. 

In leading the trainee from the known to the unknown the order 
of procedure is dependent no more on how the equipment acts 
than on how the trainee reacts. The trainee reacts best to a new 
procedure when that procedure is convincingly logical. 

(4) Finally, the most effective training films are works of art. 



Nov., 1944 THE TRAINING FILM 351 

A production is an artistic production when it begets appreciation. 
A production is a great production when it begets in a heterogeneous 
group the appreciation desired by the artist. Such appreciation is 
emotional. The trainee must be provided with the infcrmation as 
neatly presented as possible, but, in addition, he must want to learn 
it. That desire to learn is emotional. The trainee must know what 
to do and when to do it, and, in addition, he must want to do it. 
That desire to act is emotional. 

Motivation to change behavior may depend upon many factors. 
If the trainee is in a state of readiness, straight information may be 
enough. Readiness may have been developed in the trainee previous 
to the showing of the picture, but the training film maker can rarely 
be sure of that condition. If the trainee is not in a state of readiness 
to learn or to act (and the training film maker, in the majority of 
cases, must assume that he is not) the film has a responsibility for 
motivation in learning and action. Such motivation is emotional. 

Thus, to produce the necessary emotional response, every training 
film, in a sense, must be a great artistic production. Responsible 
for motivating the greatest possible number of a heterogeneous group 
it must possess a variety of emotional appeals. The expert in the 
use of music cannot rely on that medium alone. Some of the trainees 
may be reached by the music, a few by the acting, others by the 
photography, by the narrator, by the tempo, by the color, or by an- 
other device. But somehow, through artistic appeal, the training 
film must reach them all. 

However, it is not safe to assume that the desired motivation 
will be achieved automatically because a variety of appeals has been 
used. Men are trained far from home. They may see films when 
they are jaded and frustrated. The grave situations in which men 
train call for a persistent search for appeals that are appropriate. 

A training film will evoke an appreciation no greater than the 
effort, feeling, and inspiration that go into it. The producer, the 
writer, the photographer, the director, the cutter, and each of the 
others must ask himself, "What have I contributed that will assure 
the appreciation which will motivate to learning and to action?" 

A training film, then, to be an effective instrument for the control 
of behavior, must have 4 basic characteristics: it must be built 
in the form of a narrative, around the successful solution of a prob- 
lem; it must possess opportunities for directed identification; it 
must be convincingly logical; and it must be an artistic production. 



TREATMENT OF NAVY SLIDE FILMS FOR PSYCHOLOGIC 

IMPACT* 

JAY DRESSER** 

Summary. In preparing slide films to teach pilots in the South Pacific how to 
survive if forced down in enemy territory, the Training Film Branch has carried on . 
experimental work that has definite implications for the motion picture training film 
field. The Jap His Honorable Self, a slide film on how to "out- Jap" a Jap, pro- 
vides a good example of this experimental work. 

The initial problem was to get pilots in the final stages of operational training or on 
combat duty to be willing to view slide films to which they were frankly allergic as a 
medium smacking too strongly of the traditional classroom. 

Secondly, because of the complexity of the material to be presented, an original treat- 
ment had to be devised to achieve a psychologic impact that would enable pilots to 
remember survival facts months after viewing the film. This treatment involved fresh 
approaches in script and art work, and the use of a color process new in the 35-mm 
commercial field. 

Although a discussion of slide films may appear to be out of place 
in a meeting of the Society of Motion Picture Engineers, the experi- 
mental work carried on by the U. S. Navy in the production of a series 
entitled Theaters of War Pacific Area has definite implications for 
motion picture training film production. 

One of these films, The Jap His Honorable Self, provides a good 
example of the research work in this field. Within the space of thir- 
teen minutes it attempts to tell pilots the complex story of "what 
makes To jo tick" how to "out- Jap" a Jap in the event of capture by 
the enemy. 

Everyone has read the gruesome stories of what has happened to 
some of our pilots when forced down and captured by the Japs. To 
try to determine what a man should do in the event of capture posed 
a real problem. The unspoken reaction of many people was that it 
probably was best to keep the last shot in a .45 for just such an 

* Presented Apr. 18, 1944, at the Technical Conference in New York. 
** Lieutenant, USNR, Project Officer, Training Film Branch, Bureau of Aero- 
nautics, U. S. Navy, Washington, D. C. 
352 



TREATMENT OF NAVY SLIDE FILMS 353 

emergency. However, research indicated that there might be more 
encouraging procedures to follow. 

It is obvious that what goes on behind the horn-rimmed glasses of 
these little yellow, buck-toothed fellows is quite different from what 
"percolates" in the upper story of the average American boy. There 
are certain things a white man unwittingly can say or do that will 
drive a Jap into unreasonable fits of murderous temper, and when a 
man is an unarmed prisoner he can find it quite unhealthy to anger 
his Jap guards. 

The Navy writer and story sketch staff had the initial problem of 
visualizing a maze of abstract facts and theories in such a manner as 
to enable our men to remember how literally to keep their heads 
while enjoying the doubtful hospitality of the Nips. 

In addition to this problem, the authority requesting the material 
specified that the subject must be presented in slide-film form. 
Frankly, this posed quite a challenge. 

Pilots under the strain of operational training or combat duty have 
little or no interest in slide films. They will accept motion pictures, 
but slide films smack too strongly of the academic classroom. And 
at this stage of training, the average "hot" pilot feels that he is too 
advanced to go back to school. 

Our production crew, then, had this double-barreled problem: 

(1) A form of slide film had to be devised that pilots would accept 

and find interesting. ' 

(2) The film must present this complex subject with enough punch 

to enable men to remember it for months after seeing the 
film. 

. In o.ther words, as the professors would put it, a treatment had to 
be devised to give a psychologic impact that would insure the maxi- 
mum of learning. 

GENERAL PLAN 

Use of Color. To arouse the curiosity of training officers and 
pilots to the point where they would take a look at the film, it was 
decided to use color. In addition to the fact that the average 
person is a sucker for films in color, there were several good psycho- 
logical reasons for this choice. Not the least of these reasons is the 
basic principle that the more a training aid stimulates the visual 
senses, the more effective it will be. And, in spite of the present limi- 



354 J. DRESSER . Vol 43, No. 5 

tations of color, it is more stimulating than the world of lights and 
shadows which the black-and-white photograph portrays. 

A new type of color process, which was used to photograph this 
subject, will be discussed later. 

Simplification. The facts had to be simplified and boiled down 
to what could be shown within 15 min. Again, research had shown 
that the span of interest in training films was limited to not much 
more than a quarter of an hour. 

Moreover, it was deemed advisable to limit the narration to One 
side of a 16-in. recording. This would overcome the undesirable fea- 
tures of stopping the picture while the "platter" was turned over. 

The type of transcription disk which was cut for Navy work was 
limited to an absolute maximum of 13 min. It is not difficult to see 
why the writer, faced with the job of funneling a welter of facts into 
such a narrow space, suffered from a new form of claustrophobia. 

Use of Drawings. As another means of catching and maintain- 
ing interest, it was decided to use drawings. There were several 
other reasons for this choice : 

(1) Owing to the poor quality of available photographs on Japan, 

it would have been impossible to make satisfactory prints. 

(2) Drawings offer the advantage of complete control of subject 

matter and composition. 

Use o| the Vernacular. To wipe. out any further traces of the 
classroom, the narration attempted to use a more picturesque form 
of gab, which would be acceptable to the average pilot. 

Use of Psychology. To insure this thing called "psychologic im- 
pact," every effort was made to develop pictures that would stick 
in the mind. Unusual visual patterns and color schemes had to be 
found that would help men to remember facts by association months 
after seeing the film. The writer used figures of speech, gags, and 
other such devices that would catch the imagination and stay in the 
memory of the audience, for the chances were that most men would 
be able to see this film only once. 

PRODUCTION PROCEDURES 

Story Sketch. The plan of presenting the information was first 
developed in story-board form. One of the story sketch men, for- 
merly well known as a staff member at a West Coast studio, sug- 
gested a novel cartoon approach. It was to be the life story of an 



Nov., 1944 TREATMENT OF NAVY SLIDE FILMS 355 

average Japanese boy up to the time that our pilot might run into 
him as one of Tojo's tough little soldiers. 

Finished Frame Cards. Owing to the simplicity of the cartoon 
treatment as planned, the story sketch was made in the form of 
finished frame cards. Thus, with a staff of only 3 artists, the art 
work was planned and finished within 14 days. 

Script. The script was then written against the story sketch plan. 
Final polishing was done when the narration was read against a test 
print. 

Color Printing. The frame cards were photographed and printed 
in color by means of an iodide mordant process. Somewhat of a 
newcomer in the field of commercial 35-mm color reproduction, this 
iodide mordant process offered a relatively fast, cheap, and reliable 
process. 

The duplicates from this process gave a definition well suited to this 
type of work. Moreover, "thin" colors did not wash out when photo- 
graphed in conjunction with denser shades. 

Recording. Many ships had not used slide films simply because 
in a rolling sea the needle of the playback equipment would not stay 
in the groove of the record. Consequently, it was decided to cut 
fewer lines per inch and to plow out a groove deep enough to hold a 
needle in most conditions. The recording in this case uses about 96 
lines to the inch, which limits the total running time of a 16-in. disk 
to less than 13 min. 

The objectionable bell tone used in the average "gong opera" to 
signal change of frame was replaced by an oscillator tone carefully 
regulated to a set frequency of 370 kilocycles, which is less noticeable 
and unpleasant. 

Attempts were made to develop pace and timing in the script in 
order to keep interest from lagging. 

A narrator was found whose voice was of a frequency best calcu- 
lated to reproduce satisfactorily on the average slide-film equipment. 

RESULTS 

Though it is too early to obtain results on the use of this particular 
film in the fleet, training officers in the Bureau of Naval Personnel 
and in the Deputy Chief of Operations for Air have expressed an 
opinion that this film will be very effective. 

Others in this same series have been the first slide films to be ac- 
cepted and used by pilots in advanced operational training and in the 



356 J. DRESSER 

South Pacific. Therefore, it is believed that some element of success 
has been attained in the search to make training films that have an 
effective psychologic impact. 

However, in all humility, let it be said that the Training Film 
Branch feels that the possibilities of slide films as a versatile teaching 
tool have only been indicated. The field is wide open to great im- 
provements in film quality and treatment, and the need still exists for 
a truly foolproof automatic projector that would do away with the 
bell or oscillator changing signal. 

(Ed. Note: At the conclusion of the paper, Lt. Dresser presented the slide film, 
The Jap His Honorable Self, using a projector of the latest type designed to 
overcome the limitations of older slide-film equipment now in the field.) 



GETTING THE MOST FOR THE NAVY TRAINING 
FILM DOLLAR* 



L. R. GOLDFARB** 



Summary. The responsibility for the expenditure of funds for the production 
of training films, the making of release prints, and the purchase of miscellaneous items 
in connection with the Navy's training film program is centered in the Procurement 
Section of the Training Film Branch. 

This Section^ with a personnel of thirteen, consisting of officers, enlisted men, and 
civilians, operates in much the same manner as an efficiently run purchasing office of a 
large commercial organization. However, film producers have had to learn that the 
basis of their dealings with the Navy differs radically from the manner in which they 
had been accustomed to dealing with their commercial customers. From its in- 
ception, the Procurement Section has applied much of its energies to "indoctrinating" 
producers in Navy procurement policies and procedures. 

The Procurement Section has been almost constantly beset with various problems, 
some of which were inherently problems of the Section, but many of which were prob- 
lems merely because they were the problems of producers. At the present time, how- 
ever, most of the problems have been solved to such an extent that commercial producers 
of Navy training films are operating on an efficient basis that assures them a reason- 
able profit. At the same time, the Navy is getting the most for its training film dollar 
in quality, quantity, and timeliness. 



Still fresh in everyone's mind is the recent struggle with his in- 
come tax return and the resulting payment of his share of the heaviest 
taxes in our history most of it earmarked for war purposes. A part 
of those tax dollars a comparatively small part, it is true will be 
spent in producing and distributing training films for the United 
States Navy. Although the outlay, for this purpose is a "drop in 
the bucket" compared to the total war costs, the same concern is 
given to these expenditures as is given to the administration of 
budgets approaching astronomical proportions. The responsibility 
for the expenditure of these training film funds rests with the Pro- 
curement Section of the Navy's Training Film Branch. 

* Presented Apr. 18, 1944, at the Technical Conference in New York. 
** Ensign, USNR, Training Film Branch, Bureau of Aeronautics, U. S. Navy, 
Washington, D. C. 

357 



358 L. R. GOLDFARB Vol 43, No. 5 

The functions of the Procurement Section may be segregated into 
the following broad categories : 

(1} To negotiate and initiate contracts with commercial producers for the 

production of Navy training films ; 
(2) To negotiate and initiate contracts with commercial film laboratories for the 

processing and printing of training films ; and 
(5) To purchase other miscellaneous materials necessary to implement the 

Navy's training film program. 

Needless to say, the effective execution of these functions neces- 
sitates the performance of countless routine operations and the main- 
tenance of a myriad of records. At the present time the services of 
13 persons, including officers, enlisted men and civilians, are devoted 
to the performance of these duties. 

Anyone watching the Procurement Section in operation and being 
unaware that it is part of the Navy would think it was nothing more 
than an efficiently operated purchasing office of a large commercial 
organization. Fundamentally, he would be correct because the 
supplying of training films for the entire Navy is "big business" 
and requires big business methods. The only differences are these: 
Instead of spending the money of a comparatively limited group of 
stockholders, we are spending the money of the nation's taxpayers; 
and instead of being governed by the policies of a board of directors 
responsible to a group of stockholders, we are controlled by the poli- 
cies and regulations of the United States Navy, responsible to the 
nation as a whole. 

Those are the reasons why training film producers are soon made 
aware that the basis of their dealings with the Navy differs radically 
from the methods by which they have been accustomed to doing 
business with their commercial customers. For example, instead of 
determining the price to be charged for a film by estimating the cost 
of material and labor and adding to it a liberal percentage to cover 
overhead and profit, the producer of Navy training films is required 
to account for every dollar of his price. To some this may seem like 
"much ado about nothing"- that the amounts involved do not justify 
the meticulous attention accorded them. While it is true that the 
savings on training films may represent "small potatoes" when com- 
pared to the expenditures for the entire war effort, it must be re- 
membered that the same policy of diligence followed in spending 
many billions of dollars for countless other war needs results in an 
over-all saving which is far from being "small potatoes." 



Nov., 1944 THE NAVY TRAINING FILM DOLLAR 359 

As stated previously, one of the functions of the Procurement 
Section is to negotiate and initiate contracts with commercial pro- 
ducers for the production of Navy training films. It is to this phase 
of its work that this discourse will be limited. 

Like other sections within the Training Film Branch, the Procure- 
ment Section, in the course of its development, has experienced 
growing pains and has passed through one or more awkward stages. 
From its inception, one of the biggest problems confronting the Sec- 
tion has been the drafting of the right type of contract for training 
films one that was sufficiently flexible to protect producers against 
the contingencies of training film production, yet rigid enough to 
ensure that full value was being received for the Navy's money. 

One of the earlier types of contracts by which it had been expected 
that this could be accomplished was the so-called "range price" con- 
tract. This type of contract was simply one which established a 
minimum price and a maximum price, the final price to be between 
the minimum and maximum and determined on the basis of a state- 
ment of actual costs of production submitted by the contractor upon 
completion of the film. This type of contract had the element of 
flexibility, but eventually met with objection on the ground that it 
was too similar to a cost-plus contract, which type of contract for 
training films is not looked upon with favor by the Bureau of Aero- 
nautics. It might be explained at this point that the Training Film 
Branch is under the cognizance of the Bureau of Aeronautics, al- 
though it is responsible for furnishing training films for the entire 
Navy. 

Another type of contract that was in use for a while was a contract 
with a fixed price in which was included a specific amount for con- 
tingencies. This also eventually met with Bureau objection on the 
ground that it was contrary to changed Bureau policy. 

Another means by which training film contracts were awarded was 
through the use of the "letter of intent." Briefly, the letter of intent 
was an instrument issued to a producer authorizing him to produce a 
specified film or films and expressed the Navy's intention to award a 
formal contract prior to completion of the film. The letter of intent 
did not establish a contract price. It was merely a legal "go" signal. 
The contract price was decided upon when the production reached 
a stage of completion at which the final cost could be ascertained with 
reasonable certainty, and at that point the letter of intent was con- 
verted to a formal contract. Letters of intent were used for a com- 



360 L. R. GOLDFARB Vol 43, No. 5 

paratively long period, but were eventually discontinued as the result 
of a directive issued by the Secretary of the Navy in June 1943. 

Consideration of each of the aforementioned methods of contract- 
ing for training films makes it evident that every effort was made to 
consider the welfare and best interests of the commercial producers 
as well as the Navy. It will be noted that in each instance the ele- 
ment of flexibility was attained, thus protecting the producer against 
the unforeseeable conditions of production. The Navy's interests 
were not entirely without protection, however. They were taken 
care of in the following ways : 

( 1 ) By selecting the right producer for each project ; 

(2) By conducting negotiations with the producer prior to awarding each 

contract; 

(3) By tight control, by the Training Film Branch's Project Supervision Sec- 

tion, during production ; and 

(4) By close scrutiny of the producer's final cost as evidenced by the detailed 

cost breakdown required from every producer. 

The evolution of the contractual policies and procedures finally 
resulted in the adoption of the current policies of the Section. These 
policies, which are consistent with those of the Bureau of Aeronautics, 
assure the efficient producer a reasonable profit, and at the same time 
protect the Navy against paying for producers' errors and ineffi- 
ciencies. These policies and procedures can best be explained by 
describing a typical contract negotiation for a training film production. 

Before proceeding, however, it should be explained that under cur- 
rent procedure, negotiations for the production of a film are not 
undertaken until the master script for that film has been approved 
by all cognizant parties. The script may have been written by the 
Navy, by an independent writer, or by a producer. Let us assume, 
then, a master script has been written and approved, and that it has 
been decided to have the film produced commercially and not by 
Naval personnel. 

The first step will be to solicit a price proposal for production of 
the film from one or more of the many producers, regarding whom 
the Section has much detailed information in its files. But which 
producer or producers should be solicited for a proposal? It would 
be impracticable, obviously, to solicit every available producer each 
time a new production is contemplated. To do so would result in 
the waste of so much time that the value of the training film program 



Xov., 1944 THE NAVY TRAINING FILM DOLLAR 361 

would be almost completely neutralized. How, then, does the Navy 
choose its producers for specific projects? 

There are many factors that govern the selection of producers to 
be solicited in any given instance. As examples, consideration is 
given to the producer's proximity to the shooting locale, to the pro- 
ducer's experience and skill in the particular production techniques 
desired, whether the producer has satisfactorily produced films of a 
similar nature in the past, the producer's record as a "high-cost" or 
"low-cost" producer, his ability to deliver the film within the required 
time, and other considerations. 

When it has been decided which producers are to be solicited, a 
copy of the master script is submitted to each with a request for 
the submission of a price proposal for production of the film. The 
Navy requests each producer to submit with his proposal a cost 
breakdown showing in detail the individual items of cost which com- 
prise the total price how much for raw stock, how much for direc- 
tion, how much for photography, . etc. It is by means of this cost 
breakdown that all the pertinent facts relating to the cost of the film 
are revealed. 

The advantages of the cost breakdown are manifest. First, it 
induces the producer to estimate the cost of the film in a logical and 
orderly manner. Instead of leaning back in his chair, clasping his 
hands behind his head, looking up at the ceiling, and saying, "Well, 
let me see now. I guess it ought to cost somewhere around $10,000," 
he must give it the same careful thought that a builder would give 
to the building of a house listing everything that is expected to go 
into its construction and what each item will cost. It is not intended 
to imply that all producers, prior to their doing business with the 
Navy, used such methods of estimating the price of a film. It is a 
matter of record, however, that methods not much different were 
common practice. 

The second advantage of the cost breakdown is that it enables the 
Navy to determine the reasonableness of the price by evaluating 
each of the individual items comprising the total cost. In this man- 
ner the Navy protects itself against buying "a pig in a poke." Each 
item of cost, from raw stock to editing, from direction to overhead, 
is given individual scrutiny. When an item does not appear to be 
"reasonable," the producer is asked to explain. Once it has been 
established that the individual items are reasonable, the total price 
is considered from an over-all viewpoint. If it is not "in line," the 



362 L. R. GOLDFARB Vol 43, No. 5 

individual items are again examined to determine the reason. It 
might be explained at this point that the Procurement Section real- 
izes there is no ' 'bargain basement" for buying training film produc- 
tions, but it does not consider that as justification for paying "Fifth 
Avenue" prices. 

The cost breakdown form serves another purpose. It provides a 
convenient means of listing the specifications for a production. The 
term "specification" as used in Navy training film contracts refers to 
the various materials, labor, etc., that will be consumed in the pro- 
duction of a film. Included in the specifications of a typical motion 
picture production would be the amount of raw stock of all types, the 
number of men to be used, and the time to be spent 1 on research, script 
writing, direction, photography (production crew), etc., the type of 
sound recording, estimated cutting and editing time, equipment to 
be rented, travel locations and number of trips, number of days for 
crew subsistence, percentage of live action, animation, and stock 
footage, whether black-and-white, Technicolor, or Kodachrome, 
final edited length, and other pertinent details. 

Aside from their relationship to cost, there is a basic reason for 
requiring such detailed specifications. The specifications are 
eventually incorporated in the contract and are a source of protection 
to the producer in such cases where production changes result in in- 
creased costs. Training film contracts are not cost-plus, and the 
only justifications for an increase in price are : 

(1) The furnishing of materials or services which are in addition to, or dif- 

ferent from, what was originally contracted for; and 

(2) Increases in cost due to causes beyond the control of the contractor. 

Prior to the policy of incorporating production specifications in 
training film contracts, it was frequently difficult to amend contracts 
upward. This was so because the contracts lacked specific details 
of what the price purported to cover, and it was, therefore, difficult 
to establish, contractually, that a requested increase in price was due 
to a change in specifications and not to errors of judgment on the 
part of the contractor. To remedy this situation, complete specifica- 
tions similar to those previously referred to are now included in all 
training film contracts. Thus, when a producer's costs are increased 
because of changes, that fact can be established more easily and is 
given recognition by the Counsel's Office of the Bureau of Aeronautics 
as sufficient reason for amending the contract. 



Nov., 1944 THE NAVY TRAINING FILM DOLLAR 363 

Let us assume, then, that at this point the cost details and specifica- 
tions have been reviewed and the producer for the film has been 
selected. The next step is to request the Contracting Officer of the 
Bureau of Aeronautics to award a contract to the producer selected. 
Before the contract is awarded, however, the request must pass 
through certain other sections in the Bureau, each one forging a link 
in the chain of routine operations which leads from the contractor's 
letter of proposal to the awarding of the formal contract. 

One of the sections through which the request for contract passes 
is the Office of Procurement and Material Liaison, commonly re- 
ferred to as OP&M. This Section, which maintains liaison with 
similar OP&M sections in other Navy bureaus and with the Army 
procurement activities to exchange information on contractors' 
prices and procedures, reviews all price proposals with the particular 
section requesting the contract. Although the result of negotiations 
conducted by the Training Film Procurement Section usually is ac- 
cepted, it is often necessary to furnish OP&M Liaison with detailed 
explanations of various items of cost contained in requests for con- 
tracts. This explains partially the necessity for the Procurement 
Section to probe deeply into each proposal before requesting a con- 
tract. 

After the contract has been awarded and the producer has com- 
menced production, the Navy frequently requests changes involving 
increases in cost. For purposes of expediency, the Navy Project 
Supervisor assigned to the project is given authority to authorize 
individual changes which involve an estimated additional cost of not 
more than $1000. If a change involves an expenditure of more than 
$1000, the approval of the Training Film Branch is necessary. Be- 
fore completion of the film the producer may consolidate all of these 
authorized changes into one request for an amendment to the con- 
tract. Training film contracts, as currently drafted, also provide 
for increasing the price of a contract for additional costs resulting 
from causes beyond the control of the contractor. Chief of these 
causes is "stand-by" time due to adverse weather conditions and un- 
availability of Naval personnel or equipment. 

Thus it can be seen that the type of contract now in use has the 
quality of flexibility desirable and necessary in training film con- 
tracts, yet adequately protects the Navy's interests. In effect, the 
Navy says to the producer, "We agree to pay you so many dollars 
for producing a film in accordance with the approved master script 



364 L. R. GOLDFARB Vol 43, No. 5 

upon which your proposal was based. If we request you to make any 
changes which involve additional costs, the contract price will be in- 
creased accordingly, or if circumstances beyond your control neces- 
sitate additional expenditures, the contract price will likewise be in- 
creased. If, however, your actual cost exceeds the contract price 
because you estimated incorrectly or were inefficient, you will be 
paid the contract price only." 

There are many cases in which changes requested by the Navy 
result in decreased costs. Situations such as these are taken care of 
by including in most contracts a "reduction in contract price" clause. 
The practical effect of this clause is to reduce the price of the contract 
if the producer's final costs plus a reasonable profit are less than the 
contract price. 

Evidence of the effectiveness of the Procurement Section's policies 
and procedures may be found in the results of audits of training 
film producers' records. These audits are conducted by the Navy 
Supervisory Cost Inspectors of the various Naval Districts. Such 
audits have revealed that the majority of the firms producing films 
for the Navy are earning what the Navy considers a reasonable profit. 
In the few cases in which the profits earned exceeded what is con- 
sidered a reasonable rate, the causes were found to be due primarily 
to differences between the Navy's and the contractor's methods of 
computing costs. 

Officers of the t Procurement Section maintain personal contact 
with producers by periodic visits to the producers' places of business. 
Experience has proved that by meeting the producer on his home 
grounds it is much easier to become acquainted with his problems. 
It is realized that only when producers' problems, whether they re- 
late to finances, production, procedure, contractual matters, etc., 
are ironed out can the utmost efficiency be expected. These visits 
also enable the officers to familiarize themselves with the producers' 
facilities and methods of operation. 

To facilitate contact with producers located on the West Coast, the 
Procurement Section has an officer representative stationed in that 
locality, attached to the United States Naval Photographic Services 
Depot in Hollywood: All negotiations and other details involving 
the procurement of training films on the West Coast are handled by 
this officer, and the results are forwarded to the Training Film Branch 
in Washington for final action. The presence of this representative 
on the West Coast reduces materially the disadvantages arising from 



Nov., 1944 THE NAVY TRAINING FILM DOLLAR 365 

being separated from these producers by the width of the continent. 

Although this discourse is limited mainly to a discussion of that 
phase of the Procurement Section's activities which relate to the 
production of training films, it would not be complete without men- 
tioning that a large part of the responsibilities of this Section per- 
tains to the purchasing of materials and services for the making of 
release prints of training films for distribution to Naval activities 
all over the world. As a matter of fact, the amount of money spent 
for the making of release prints is only slightly less than the ex- 
penditures for productions, and the same attention to details that is 
given the expenditures for productions is given the expenditures for 
prints. To give some idea of the magnitude of this particular phase 
of the Procurement Section's activities, the total length of release 
prints purchased in the last 12 months alone approximated 35,000 
miles enough to encircle the earth almost one and one-half times, 
and enough to keep a single projector runnirig 24 hr a day, every day, 
for approximately 9 years! 

The Training Film Branch is appreciative of the efforts of the com- 
mercial organizations who have made it possible for the Navy to % 
train its personnel more quickly and more effectively than ever before. 
Most of them have put patriotism above personal gain and have co- 
operated to the fullest extent in enabling the Navy to get the most for 
its training film dollar in quality, quantity, and timeliness. 



IT IS TO LAUGH* 
J. E. BAUERNSCHMIDT** 

Summary. The best teaching is that which is done in a relaxed atmosphere one 
in which the students are in sympathy with the instructor. Therefore, when a training 
film is used as an aid to the instructor, it should also to some degree provide a measure 
of relaxation. One of the most effective methods of creating a relaxed atmosphere is 
by the use of humor. 

In film form, humor may manifest itself in many ways. There is the humor of 
negative example, of situation, and of plot. There is narrative humor, pictorial 
humor, custard-pie humor, and the subtlety of camera humor. These various types of 
humor may be blended so that the resulting laugh is derived from the combination of any 
two or even three of these techniques. 

But, however the humor is achieved, it may serve as a genuine neur other apeutic 
measure to the men who view the films aboard ships at sea, or at shore stations at distant 
advance bases, and create a closer union between the teacher and the taught. 


Humor at its best is a fluid and transitory element. Anatomically 
considered, the result of humor is the sensation of feeling good all over 
and showing it principally in one spot. The common denominator 
of humor is the contact of incongruous ideas which generates the 
element of laughter. If you say to a man "Here's a nickel, drop 
down to the corner and get me a cigar" and he drops through a trap 
door and disappears, that is humorous, but not even the experts 
can tell you why. E. B. White, a professional humorist, says, 
"Humor is a final emotion, like breaking out into tears. A thing gets 
so bad and you feel so terrible that at last you go to pieces and it's 
funny. Laughter does just what tears do for you. My life as a 
humorist began in a Child's restaurant when a waitress spilled butter- 
milk down my neck. That great smear of wet white coming down 
over a blue serge suit, and her words ' !' were the turning point 
in my career." 

The philosophers Kant and Pascal agreed that the essence of 

*Presented Apr. 18, 1944, at the Technical Conference in New York. 
""Lieutenant (j. g.), USNR, Training Film Branch, Bureau of Aeronautics, 
U. S. Navy, Washington, D. C. 
366 



IT Is TO LAUGH 367 

humor was in starting toward a plausible goal, and ending up no- 
where at all; thus Groucho Marx's familiar "When I, came to this 
country I didn't have a nickel in my pocket. Now I have a nickel 
in my pocket!" Sigmund Freud propounds the belief that humor 
and laughter are both based on the release of the subconscious will. 
The trouble is, there are all kinds of humor. Some is derisive, some 
sympathetic, and some merely whimsical. That is what makes 
comedy so much harder to create than serious drama. People laugh 
in many different ways. They cry in only one. 

But whatever the proper definition of humor may be, laughter is 
as much a part of the temperament of America as baseball, or trying 
to get something for nothing. And if it is agreed that teaching must 
be in tune with the temperaments of the taught, then there can be no 
question that laughter should be a part of our teaching devices 
specifically, our training films. Teaching is, at its best, guidance. 
For guidance to be effective, the instructor must first win the affec- 
tions and confidence of his students. This cannot be accomplished 
in the Olympian isolation of precious, exclusive dignity. The de- 
fense for dignity is that it engenders respect. But the reward of a 
frozen face is a lukewarm lesson. 

Laughter is a psychological whip which may snap an audience 
into alertness. How many of you have seen a dull scene or sequence 
livened up with a humorous twist, and noticed how immediately 
the air is surcharged with eagerness. There is something in the mere 
act of laughing which jostles a person both physically and mentally 
and jiggles his equilibrium. A group of students who are alert will 
learn better than those who are apprehensive or uninterested. 

Moreover, so far as it eliminates emotional blocking, laughter is a 
stimulant to learning. By emotional blocking is meant that state 
of mental constipation that results from apprehension, annoyance, 
or tension. Any newly indoctrinated reserve officer who suffered 
the rigors of Indoctrination School knows what tension in the learning 
process is. The absolute necessity of learning fast imposes a mental 
hazard to the process that is not easy to overcome. Relaxation in 
learning is essential, and the subjects that were easiest to learn were 
those that were presented in the most interesting and relaxed manner. 

Fear is a strong inhibition to the acquisition of learning. Fear 
paralyzes. An individual afraid is in no mood for intellectual ad- 
ventures. There is nothing like laughter to route a bogy. Reports 
from the fleet reveal that men, as they near the combat area, forsake 



368 J. E. BAUERNSCHMIDT Vol 43, No. 5 

classrooms, manuals, charts, and all other aids to learning, but they 
will look at films, perhaps for deriving some measure of relaxation 
from the tradition of entertainment that films provide. In film 
planning for men of the fleet, we must capitalize on this preference 
for films as a teaching medium. We must make them entertaining 
as well as authoritative, for a relaxed audience is one that will learn 
more. 

Akin to fear is worry. It precludes concentration and stifles 
initiative. But care can be laughed away. People turn to levity 
and amusement in order to forget their anxieties. Comedians from 
ancient times on have been regarded as healers for the oversolicitous. 
The need for mental therapy inherent in humor is tremendous among 
personnel afloat and at advance bases. 

Moreover, it is a psychological truism that subconsciously we 
tend to forget the unpleasant and remember the pleasant. Hilarity 
is so pleasurable that everything connected with it becomes some- 
thing to enjoy and to preserve in the memory. The happy learning 
creates the deepest impression. 

With technical subjects, humor may be an ignition spark to the 
mental engine. A student is stumped. No matter how repeatedly 
or how variously something is explained, he is stopped at the point 
of comprehension. Then something occurs to start him laughing. 
And suddenly the solution becomes clear. It is a strange phenom- 
enon, but it works. The blocking is probably caused by intellectual 
or neural rigidity brought on by an anxiously fixed mind. The 
individual tries so hard to scale the barrier along his line of attack 
that his mind gets one tracked. It loses its flexibility. What is 
needed is some distraction to jerk the reason back to normal. And 
laughter is an eminently satisfactory distraction. 

The simplest type of film comedy the one that will most readily 
produce a laugh is the comedy of negative example. It is the 
comedy of the unpleasant taken playfully. It may be divided into 2 
categories : the sympathetic, and the derisive or derogatory. Sym- 
pathetic negative example is best used where the subject material is 
difficult either to perform or to comprehend, and where we do not 
expect the student to acquire comprehension without a certain de- 
gree of difficulty. The derisive or derogatory technique is best used 
where the subject material is easy to comprehend, and where we 
expect the student to acquire comprehension immediately, if, indeed, 
he does not already possess it, This is the comedy of superiority. 



Nov., 1944 IT Is TO LAUGH 369 

By implication, the film says, "We here in the audience are a good 
deal wiser than this jerk!" Thus, we teach by indirection. We put 
our teaching on an assumptive level. We flatter the audience and 
win their affection and support. 

Another type of film comedy is the comedy of allegory. In 
ancient times the actors wore masks which immediately indicated 
to the audience the mood and character of the player. The film 
form that begins with a shot of a naval aviator with wings, knocking 
at a highly imaginative interpretation of St. Peter's gates, sets a 
mood immediately. It becomes obvious from the very first scene 
just exactly the point of view the film intends you to assume. It, 
too, is the comedy of assumption, coupled with the humor of negative 
example. It is particularly suited to the motion picture medium 
because it provides unlimited opportunities for the use of the imagina- 
tion. This type of film humor is slanted for an audience that "knows 
better," but its treatment is such that it can be "preachy" without 
being offensive. It can be highly sarcastic and continue to be highly 
amusing. 

The humor of parody or caricature achieves its effect by means of 
grotesque or ludicrous exaggeration, or by means of distortion by 
exaggeration of parts or characteristics. It tickles the funny bone 
and provides a pleasurable experience. Thus a film on handling 
heavy loads may be brightened immeasurably by a live action shot 
or a cartoon insert of a typical sailor overwhelmed by a pile of bed- 
ding, clothing, cleaning gear and ammunition staggering manfully 
along to the accompaniment of a bright comedy musical signature. 

Animation gives us the facility to visualize anything the brain 
can imagine or the hand can draw. To create an atmosphere of 
acceptance based on laughter, animation can be used to good ad- 
vantage in training films either as an introductory device, or as a 
parenthetical vehicle to emphasize a point. The introductory tech- 
nique is most effective in creating an atmosphere of relaxation. A 
film on damage control may be enlightened by a 40-sec introductory 
cartoon animation sequence which reveals a Japanese shark sawing a 
hole in the hull of a boat, and the ensuing slapstick comedy that re- 
sults when a sailor uses everything he can get his hands on to plug 
up the hole. This technique says, "Relax boys, we are going to 
teach you something here about damage control. But don't let it 
scare you, it's really a very simple proposition." Thus the film 
starts out with the students in a receptive mood. Anyone who has 



370 J. E. BAUERNSCHMIDT Vol 43, No. 5 

addressed an audience knows the value of getting it on your side at 
the very beginning. You have got to break the ice. 

Animation as a parenthetical vehicle to emphasize a point provides 
a film exclamation point. It affords a moment of visual pleasure 
and aids retention. If it is necessary to emphasize the fact that much 
care must be taken when unloading a pistol clip to prevent the spring 
from uncoiling in your face, the fact will be remembered if in cartoon 
animation a dopey character unloads the clip the wrong way and al- 
most has his head knocked off in the resulting catastrophe. 

As a parenthetical device, animation can be designed to present a 
problem in a simplified form, to reduce it to its simplest terms, and 
translate the terms by means of a comedy device. 

Perhaps the most difficult and most desirable type of comedy to 
achieve is the comedy of situation plot comedy. This may be 
broken into 2 categories: first, the comedy of a natural situation; 
and second, the comedy of an artificial or created situation. If a 
writer lives with and takes a part in the activity or operation he is 
commissioned to write about, he will find much natural humor that 
needs no elaborate staging to be presented effectively. But when a 
writer tries to invent a situation by creating a funny episode, he may 
be tripped up by the fact that the episode may not be natural to the 
situation. Such a device is strained and unfunny. It is too obvious 
a play for a laugh. The humor of a natural situation requires a 
nicety of perception and judgment on the parts of both the writer 
and the director. It must be considered carefully before being 
enacted before the camera. 

The comedy of an artificial situation is easier to create. "Pratt- 
fall" comedy is a part of this category. It is easy to place a hammer 
so that the actor will cause it to fall on his head. It is difficult to 
create natural humor in handling the hammer so that it is funny 
without being slapstick. 

Another type of humor is narrative humor. The writer of a 
script that is breezy but not smart alecky is a valuable gentleman. 
A "between-us-boys" narrative tone wins attention immediately 
and makes the audience feel that The Voice is in the know a regu- 
lar guy. Humorous narrative is the opposite from oracle-like style 
that is boring, soporific, and offensive. The narrative that speaks 
the language of the audience for which the film was designed is 
better apt to succeed than the narrative that is precious to a fault, 
and pedagogical beyond all comprehension. 



., 1944 IT Is TO LAUGH 371 

Simple pictorial comedy may often be employed to brighten up 
an otherwise dull graphic presentation. When statistics must be 
presented in film form, they may be relieved by the judicious use of 
humorous sketches. 

Finally, the technique of the running gag is particularly suited to 
the film medium. This is the technique in which we establish in the 
opening sequences of our film a situation that is ludicrous such as a 
sad-faced sailor working feverishly but ineffectively to assemble a 
mechanical device and from time to time cut back to him still at 
work on the device and still as unsuccessful as he was in the beginning. 
This is a form of sympathetic negative example that can win friends 
and influence audiences. 

And so the types of film humor that find a place in training films 
may be classified as follows : 

(1) The Comedy of Negative Example. 

(a) Sympathetic. 

(b) Derisive or derogatory. 

(2) The Comedy of Allegory. 

(5) The Comedy of Parody, 
(a) As a film entity. 
(6) As an introductory device. 

(c) As a parenthetical device to emphasize a point. 

(4} The Comedy of Situation or Plot. 

(a) The humor of a natural situation. 

(b) The humor of an artificial situation. 

(5) Narrative Humor. 

(6) Pictorial Humor. 

(7) The Humor of Camera Subtlety. 

There may be other types of comedy that have been omitted here, 
and there may be combinations of any two or more of the types of 
humor outlined above. But regardless of their types, they can 
and should be translated into film terms and used in the planning of 
training films to better insure response from and effectiveness on the 
vast audiences to be taught. 



THE CAMERA VERSUS THE MICROPHONE 
IN TRAINING FILM PRODUCTION* 



HERBERT R. JENSEN** 

Summary. The training film is primarily a motion picture, not a sound track 
illustrated with pictures. A training film succeeds in its mission to the extent that it 
can maintain eye-attention, and consequently interest. The major responsibility for 
arousing and sustaining interest is the job of the camera, not the microphone, as is too 
infrequently demonstrated. The substitution of track modulations for pictures results 
in a deadly kind of training film, effective only as a sleep-producer or sedative. Sub- 
verting the track and placing the burden of maintaining interest on the camera, where 
it rightfully belongs, will result in training films that are stimulants. 

New techniques and new equipment may be needed to fully exploit the camera. 
Whatever motion picture engineers can do to increase the flexibility and mobility of the 
camera, especially in non-studio use, will help. 

The state of the art of producing training films, despite the volume 
achieved, still leaves much to be desired. This paper will point out 
a principal shortcoming of the art as it is presently practiced, from 
the point of view that the primary power of the screen (in instruction 
or entertainment) lies in its ability to maintain attention and interest 
through the eye rather than the ear. 

The function of the training film is to present its subject primarily 
to the visual and not the auditory sense. The film's instructive 
power comes through seeing, not hearing, as is so admirably stated in 
the Chinese phrase, "one hundred hearing not so good one seeing." 

The fact that the motion picture was originally designed for the 
sense of sight is too often forgotten in writing and producing a train- 
ing film. The word "writing" is stressed, for that is where the fault 
too often lies; scripts are written rather than pictured. This is 
understandable for we have been able to use and manipulate words for 
hundreds of years while we have had less than 50 years of practice 
in using and manipulating pictures. The adoption of the policy of 

* Presented Apr. 18, 1944, at the Technical Conference in New York. 
** Lieutenant, USNR, Training Film Branch, Bureau of Aeronautics, U. S. 
Navy, Washington, D. C. 
372 



THE CAMERA VERSUS THE MICROPHONE 373 

using the spoken word instead of the picture is not from lack of 
knowledge. The experience gained from the days when films were 
silent taught us otherwise. 

The extent to which the word has been used instead of the picture 
is indicated by the results of an analysis of a few typical scripts. 
The script of a picture judged an excellent production had a word-to- 
scene ratio of 3 to 1, 3 words per scene. The script for another 
picture that had "sleeper" tendencies had 38 words per scene. It is 
admitted that this method of judging the effectiveness of a film is a 
crude one, but it does give some indication of the extent to which 
words have been substituted for pictures. The quality and effec- 
tiveness of a training film are undoubtedly related to the word-scene 
ratio, and the lower the ratio the better the film. 

A further indication that the camera has not been used efficiently 
is the oft-heard remark that training films put men to sleep. The 
auditory sense, as may be proved by this discussion is a powerful 
sedative, and even its use here may put you to sleep. The same thing 
happens in the training film, or more accurately stated, the film 
lecture in which the eye is subverted by the ear. If the audience 
sleeps the picture fails. One of the reasons why men sleep may lie 
in the fact that the screen does not hold the eye because words have 
been substituted for pictures and the film thereby fails to maintain 
the attention of the learner. To avoid this the eye must receive the 
major impact and not the ear. 

The problem of maintaining attention is also related to film length. 
Many training films are longer than they need be because of in- 
adequate handling of the screen image. Not enough of the right 
pictures are used in the right way, with the result that the track 
has to say the things the screen does not say. Word explanation is 
less efficient than picture explanation, and the greater the number of 
words needed to explain the item under instruction the more feet of 
film needed to carry them. This overdependence on narrative ex- 
planation results in a sound track packed with voice modulations 
from beginning to end with nary a pause in between. The constant 
bombardment of words on the auditory nerves dulls them and the 
learner is lulled to insensibility. Adroitly used, the narrated track 
must allow pauses between sentences and paragraphs. Phrasing 
sound and silence is necessary if the mind is to absorb and make each 
'thought presented its own before the next one drives it out. 

Training film makers must learn that some silence is golden, es- 



374 H. R. JENSEN Vol 43, No. 5 

pecially that resulting from the cessation of the narrator's voice. 
The camera must be employed in a manner that will permit the 
screen to form a silent and attentive bond between it and the view- 
er's eye, aided by the microphone only when and where absolutely 
necessary. 

It is easy to see why the microphone has become a "Quisling," so 
to speak, because of its subversive activity in undermining the job 
of the camera. It could not have become so without its being aided 
and abetted by film makers who used it as a tool, something that 
could be had easily and manipulated without much trouble. The 
ease with which a sentence is conjured up, reworked, rewritten, 
erased, and formed again is simple compared to the labor involved in 
conceiving the most efficient picture images. Further, the sentence 
can always be changed with ease; a picture image can seldom be 
changed or manipulated without the expenditure of considerable 
time, energy, and money. The subsequent delivery of a sentence to 
a microphone in a modern comfortable recording studio is nothing 
compared to the difficult manipulation of a camera on location. 
Contrast these working conditions with those confronting the camera. 

Cameramen doing Navy location shooting are required to work 
under handicaps that seldom exist in the studio. Much of the 
Navy's camera work could be classified as "triphibian," involving as 
it does photography on land, at sea, and in the air with attendant 
problems almost as complicated as those involved in this type of 
warfare. The cramped quarters of a bridge or an engine room, the 
unstable platform of a landing boat or an airplane make camera 
handling hard work. The narrow passageways and the vertical or 
near-vertical ladders that must be traversed with heavy equipment 
to gain access to the various parts of a ship involve almost as much 
sweat, if not blood, as is involved in following a trail in New Guinea. 
It is not without cause that once a camera position is achieved it 
seems that it is seldom abandoned until every usable foot that can 
be extracted from the scene has been shot. Why move in to get a 
close-up or another angle when the item can be described so much 
more easily in the sound track? And so the microphone takes over 
the camera's work, the audience goes to sleep and the information fails 
to become part of the learner's experience. 

What should happen instead of this is that the camera should be 
used to isolate, describe, and explain the item, relegating the nar-" 
rated track to the background in a merely supporting role. The 



Nov., 1944 THE CAMERA VERSUS THE MICROPHONE 375 

camera should be used as a pointer, moving in, out, and across the 
scene as dynamically as the galvanometer on a recorder.. Atten- 
tion should be aroused and maintained by the camera's ability to 
interest and excite the eye. 

The type of camera handling desired is of a level that would deliver 
to the screen an effect similar to that which the human being gets 
with his own eye. The effect to be striven for is the appearance of 
the same fluid mobility that the human eye enjoys in examining an 
object. This would result in more effective training films because of 
the subsequent increased eye attention to the screen. In this re- 
gard we should err on the side of using too many pictures rather than 
too few. The one act of going all-out for pictures and using words 
only when practically forced to, will put the camera back in its right- 
ful role. 

Now in all this what part of it relates to the work of the motion 
picture engineer? Some subversive activity on his part directed at 
the microphone, or the amplifiers, or the recorders? Not that, but 
rather constructive work on the camera's home front. 

Mobility and ease of manipulation of the camera have been prob- 
lems receiving attention for some time, but mostly in relation to studio 
use. If all training films could be produced under controlled studio 
conditions, the present equipment would be adequate. This is 
seldom the situation confronted, however. What studio could ar- 
range space and accommodations to handle a battleship or a battle 
force, an army or an air force, even if it could get them? Since 
the mountain cannot be moved to Mahommet, Mahommet must be 
moved to the mountain. Lighter, versatile equipment of all types 
is needed to make this move easier and to insure that it is made. 

The extensive application of light metal alloys in camera and 
accessory equipment will take some of the curse off the handling of 
equipment. Lighter cameras, tripod heads, tripods, battery cases, 
and so on, would free cameramen and their crews of the sometimes 
killing weight of equipment that has to be moved. Collapsible, light- 
weight magnesium dollies and tracks would aid in making it possible 
to move the camera in and out, to permit it to be used as a pointer. 
Perhaps a spring-suspended gyrostabilized camera head can be de- 
signed which would permit moving the camera on locations where 
track cannot be laid. Lightweight collapsible camera platforms 
would be of considerable use. If these were fitted with detachable 
pneumatic tires they could be used to move the object into and away 



376 H. R. JENSEN 

from the camera in situations where it would be difficult to move the 
camera smoothly. 

Because the photography involved in making training films must 
be done under handicaps not found in studio work, attention should 
be directed at making the camera as mobile as possible. The pen is 
mightier than the sword. Freeing the camera would make it mightier 
than the pen and subsequently the microphone. Paraphrasing an 
old saw, it is ' 'every camera to itself and may the microphone take 
the hindmost." 



CURRENT LITERATURE OF INTEREST TO THE MOTION PICTURE 

ENGINEER 



The editors present for convenient reference a list of articles dealing with subjects 
cognate to motion picture engineering published in a number of selected journals 
Photostatic or microfilm copies of articles in magazines that are available may be 
obtained fro,m The Library of Congress, Washington, D. C., or from the New York 
Public Library, New York, N. Y., at prevailing rates. 



American Cinematographer 

25 (Aug., 1944), No. 8 

Recent Advances in the Physics of Color (p. 259) 
Color Filters and Their Use (p. 260) 
Film Production in Argentina (p. 261) 
Tropical Problems in Aerial Camera Maintenance (p. 263) 
Kodachrome and Exposure Meters (p. 265) 
Television Needs Hollywood's Ace Cinematographers 
(p. 266) 

British Kinematograph Society, Journal 

7 (Apr -June, 1944), No. 2 
Consistency in the Laboratory (p. 47) 
The Design of Sub-Standard Sound Projectors (p. 63} 

Electronic Engineering 

17 (July, 1944), No. 197 
Maintenance of Quality in Film-Recorded Sound 

17 (Sept., 1944), No. 199 
Electronic Colour Television (p. 140) 

Electronic Industries 

3 (Aug., 1944), No. 8 
Recording Sound on Film (p. 98) 

International Projectionist 

19 (July, 1944), No. 7 
Projection Room Equipment: Its Care and Maintenance 

(P. ID 

Projectionists' Course on Basic Radio and Television (p. 7) 
Television Today, Pt. X Reproducers (p. 20) 

19 (Aug., 1944), No. 8 

The Paramount Transparency Process Projection Equip- 
ment (p. 7) 

Projectionists' Course on Basic Radio and Television, Pt. 
II, (P. 10) 



H. V. WALTERS 

W. B. LARSEN 
R. H. BAILEY 
A. WYCKOFF 

H. HALL 



M. V. HOARE 
H. CRICKS 



H. CRICKS 
J. L. BAIRD 

G. SONBERGH 



M. BERINSKY 
J. FRANK, JR. 



F. EDOUART 



M. BERINSKY 



377 



378 



SOCIETY ANNOUNCEMENTS 



How to Make Your Own Schematic Diagrams (p. 13) L. CHADBOURNE 

Television Today, Pt. XI Television Receivers (p. 18) J. FRANK, JR. 

Proper Fusing in the Projection Room (p. 21) H. B. SELL WOOD 

Radio News 

32 (Aug., 1944), No. 2 

Theater Acoustics (p. 29) W. MOODY 



SOCIETY ANNOUNCEMENTS 



The first meeting of the fall series was held by the Atlantic Coast Section on 
Wednesday evening, September 27, at the Hotel Pennsylvania, New York. 
Mr. R. E. Farnham of the General Electric Company, Nela Park, gave a talk on 
"Appraisal of Illuminants for Television Studio Lighting." In analyzing the 
various light sources used up to the present time in television studios, Mr. Farn- 
ham took 'into account such factors as (1) spectral sensitivity of the iconoscope, 
(2) requisite illumination levels, and (3) reflection characteristics of televised 
areas. 

The amount of heat in proportion to the light produced, the constancy of the 
light, and electrical interference were also discussed. Mr. Farnham compared 
light sources using mercury arc lamps, tungsten filament lamps, and fluorescent 
lamps as sources of television studio lighting. 

Following Mr. Farnham's talk Mr. Worthington C. Miner, manager of Colum- 
bia Broadcasting System's Television Department, discussed the requirements 
for studio lighting from the standpoint of television production. 



We regret to announce the death of William Lattimore Douden, 
Active member of the Society, on August 19, 1944. 



COMMITTEES OF THE SOCIETY 

(Correct to October 15) 



ADMISSIONS. To pass upon all applications for membership, applications for transfer and 
to review the Student and Associate membership list periodically for possible transfers to the 
Associate and Active grades, respectively. The duties of each committee are limited to applica- 
tions and transfers originating in the geographic area covered. 

(East Coast) 
A. S. DICKINSON, Chairman 

28 West 44th St. 
New York 18, N. Y. 

M. R. BOYER JAMES FRANK, JR. D. E. HYNDMAN 

H. D. BRADBURY GEORGE FRIEDL, JR. HARRY RUBIN 

(West Coast) 
EMERY HUSE, Chairman 

6706 Santa Monica Blvd. 
Hollywood 38, Calif. 

C. W. HANDLEY W. A. MUELLER 

H. W. MOYSE H. W. REMERSHIED 

BOARD OF EDITORS. To pass upon the suitability of all material submitted for publica- 
tion, or for presentation at conventions, and publish the JOURNAL. 

A. C. DOWNES, Chairman 

Box 6087 
Cleveland 1, Ohio 

J. I. CRABTREE A. M. GUNDELFINGER C. R. KEITH 

A. N. GOLDSMITH C. W. HANDLEY E. W. KELLOGG 

A. C. HARDY 

CINEMATOGRAPHY. To survey the field of motion picture photography in an en- 
deavor to bring before the Society any information on current or future practice, and also to 
continually review this field for possibilities of standardization of any specific procedure. 

J. W. BOYLE, Chairman 

1207 N. Mansfield Ave. 
Hollywood, Calif. 

C. G. CLARKE * ARTHUR MILLER ARTHUR REEVES 

KARL FREUND JOSEPH RUTTENBERG 

COLOR. To survey the field of color in motion picture photography in an endeavor to bring 
before the Society any information on current or future practice, and also to continually review 
this field for possibilities of standardization of any specific procedure. 

R. M. EVANS, Chairman 

Research Laboratory 
Eastman Kodak Co. 
Rochester 4, N. Y. 

F. T. BOWDITCH A. M. GUNDELFINGER 

L. E. CLARK A' C, HARDY 



* Advisory Member, 



COMMITTEES OF THE SOCIETY 

CONVENTION. To assist the Convention Vice-President in the responsibilities pertaining 
to arrangements and details of the Society's technical conventions. 

W. C. KUNZMANN, Chairman 

Box 6087 
Cleveland 1, Ohio 

J. G. FRAYNE SYLVAN HARRIS O. F. NEU 

"JULIUS HABER H. F. HEIDEGGER R. O. STROCK 

EXCHANGE PRACTICE. To survey the field of exchange practice in an endeavor to bring 
before the Society any information on current or future practice, and also to continually review 
this field for possibilities of standardization of any specific procedure. 

A. S. DICKINSON G. K. HADDOW N. F. OAKLEY 

*T. FAULKNER SYLVAN HARRIS A. W. SCHWALBERG 

G. R. GIROUX L. B. ISAAC J. SICHELMAN 

H. C. KAUFMAN 

FELLOW MEMBERSHIP. To consider qualifications of Active members as candidates for 
elevation to Fellow members, and to submit such nominations to the Board of Governors. 

EMERY HUSB, Chairman 

6706 Santa Monica Blvd. 
Hollywood 38, Calif. 

M. R. BOYER A. N. GOLDSMITH W. C. KUNZMANN 

A. S. DICKINSON HERBERT GRIFFIN L. L. RYDER 

A. C. DOWNES C. W. HANDLEY E. A. WILLIFORD 

D. E. HYNDMAN 

HISTORICAL AND MUSEUM. To collect facts and assemble data relating to the historical 
development of the motion picture industry, to encourage pioneers to place their work on record 
in the form of papers for publication in the JOURNAL, and to place in suitable depositories equip- 
ment pertaining to the industry. 

J. E. ABBOTT, Chairman 

11 West 53d St. 
New York 19, N. Y. 

O. B. DEPUE RICHARD GRIFFITH TERRY RAMSAYE 

HONORARY MEMBERSHIP. To diligently search for candidates who through their 
basic inventions or outstanding accomplishments have contributed to the advancement of the 
motion picture industry and are thus worthy of becoming Honorary members of the Society. 

E. A. WILLIFORD, Chairman 

30 East 42d St. 
New York 17, N. Y. 

J. I. CRABTREB EMERY HUSE 

A. N. GOLDSMITH L. L. RYDER 

JOURNAL AWARD. To recommend to the Board of Governors the author or authors of 
the most outstanding paper originally published in the JOURNAL during the preceding calendar 
year-to receive the Society's Journal Award. 

SYLVAN HARRIS, Chairman 

8621 Georgia Ave. 
Silver Spring, Md. 

F. G ALBIN C. R. KEITH 

J. G. FRAYNE J. A. MAURER 



* Advisory Member. 



COMMITTEES OF THE SOCIETY 

LABORATORY PRACTICE. To survey the field of motion picture laboratory practice in 
an endeavor to bring before the Society any information on current or future practice, and also 
to continually review this field for possibilities of standardization of any specific procedure. 

H. E. WHITE, Chairman 

Room 813 

350 Madison Ave. 

New York 17, N. Y. 

A. C. BLANEY G. H. GIBSON J. M. NICKOLAUS 

L. A. BONN EMERY HUSE N. F. OAKLEY 

A. W. COOK T. M. INGMAN W. H. OFFENHAUSER, JR. 

O. B. DEPUE C. L. LOOTENS V. C. SHANER 

R. O. DREW *A. J. MILLER J. H. SPRAY 

J. A. DUBRAY H. W MOYSE J. F. VAN LEUVEN 

J. G. FRAYNE J. R. WILKINSON 

MEMBERSHIP AND SUBSCRIPTION. To solicit new members, obtain nonmemher sub- 
scriptions for the JOURNAL, and to arouse general interest in the activities of the Society and its 
publications. 

JAMES FRANK, JR., Chairman 

356 West 44th St. 
New York 18, N. Y. 

T. C. B ARROW^ E. R. GEIB W. A. MUELLER 

J. G. BRADLEY L. T. GOLDSMITH H. B. SANTEE 

KARL BRENKERT SYLVAN HARRIS G. E. SAWYER 

G. A. CHAMBERS L. B. ISAAC W. L. THAYER 

L. W. CHASE W. C. KUNZMANN C. R. WOOD, SR. 

J. P. CORCORAN S. A. LUKES E. O. WILSCHKE 

J. G. FRAYNE G. E. MATTHEWS W. V. WOLFE 
G. C. MISENER 

NONTHEATRICAL EQUIPMENT. To survey the field of nontheatrical motion picture 
equipment in an endeavor to briftg before the Society any information on current or future prac- 
tice, and also to continually review this field for possibilities of standardization of any specific 
procedure. 

J. A. MAURER, Chairman 

117 East 24th St. 
New York 10, N. Y. 

*F. L. BRETHAUER R. C. HOLSLAG *T. J. RESS 

F. E. CARLSON R. KINGSLAKE L. T. SACHTLEBEN 

JOHN CHRISTIE D. F. LYMAN A. SHAPIRO 

R. O. DREW W. H. OFFENHAUSER, JR. D. G. SMITH 

F. M. HALL M. W. PALMER M. G. TOWNSLEY 

J. A. HAMMOND A. G. ZIMMERMAN 

PAPERS. To solicit papers, and provide the program for semi-annual conventions, and make 
available to local sections for their meetings papers presented at national conventions. 

BARTON KREUZER, Chairman C. R. DAILY, Vice-Chairman 

RCA Victor Division 5451 Marathon St. 

Radio Corp. of America Hollywood 38, Calif. 

Camden, N. J. 

F. T. BOWDITCH J. G. FRAYNE H. W. MOYSE 

G. A. CHAMBERS C. R. KEITH W. H. OFFENHAUSER, JR 
F. L. EICH E. W. KELLOGG V. C. SHANER 

R. E. FARNHAM G. E. MATTHEWS S. P. SOLOW 

J. L. FORREST P. A. McGuiRE D. R. WHITE 

JAMES FRANK, JR. .W. V. WOLFE 



: Advisory Member. 



COMMITTEES OF THE SOCIETY 

urvey the field for methods of 
g before the Society any infor 
this field for possibilities of standardization of any specific 



PRESERVATION OF FILM. To survey the field for methods of storing and preserving mo- 
tion picture film in an endeavor to bring before the Society any information on current or future 
practice, and also to continually review this field for possibilities of standardization of anj 
procedure. 



J. G. BRADLEY, Chairman 

The National Archives 
Washington 25, D. C. 

J. E. ABBOTT J. L. FORREST *W. F. KELLEY 

J. I. CRABTREE C. L. GREGORY TERRY RAMSAYE 

A. S. DICKINSON V. B. SEASE 



PROCESS PHOTOGRAPHY. To survey the field of process photography in an endeavor 
to bring before the Society any information on current or future practice, and also to continually 
review this field for possibilities of standardization of any specific procedure. 

WILLIAM THOMAS, Chairman 

851 Monterey Rd. 
Glendale, Calif. 

F. R. ABBOTT *F. M. FALGE GROVER LAUBE 

A. H. BOLT C. W. HANDLEY G. H. WORRALL 

*W. C. HOCH 



PROGRESS. To prepare an annual report on progress in the motion picture industry. 

G. A. CHAMBERS, Chairman 

Naval Air Station, PSL 
Anacostia, D. C. 

F. T. BOWDITCH J. A. DUBRAY G. E. MATTHEWS 

G. L. DIMMICK M. S. LESHING D. R. WHITE 



PROGRESS MEDAL AWARD. To recommend to the Board of Governors a candidate who 
by his inventions, research or development has contributed in a significant manner to the 
advancement of motion picture technology, and is deemed worthy of receiving the Progress 
Medal Award of the Society. 

J. I. CRABTREE, Chairman 

Research Laboratory 
Eastman Kodak Co. 
Rochester 4, N. Y. 

O. B. DEPUE J. A. MAURER 

G. E. MATTHEWS L. L. RYDER 



PUBLICITY. To assist the Convention Vice-President in the release of publicity material 
concerning the Society's semi-annual technical conventions. 

*JULIUS HABER, Chairman 

RCA Victor Division 
Radio Corp. of America 
Camden, N. J. 

G. A. CHAMBERS *HAROLD DESFOR G. R. GIROUX 

C. R. DAILY P. A. McGuiRE 



* Advisory Member. 



COMMITTEES OF THE SOCIETY 



SOUND. To survey the field of motion picture sound recording and reproducing in an en- 
deavor to bring before the Society any information on current or future practice, and also to con- 
tinually review this field for possibilities of standardization of any specific procedure. 



W. V. WOLFE, Chairman 

515 N. Alta Drive 
Beverly Hills, Calif. 

M. C. BATSEL 
D. J. BLOOMBERG 

B. B. BROWN 

F. E. CAHILL, JR. 

C. R. DAILY 

L. T. GOLDSMITH 



C. R. KEITH, Vice-Chairman 
195 Broadway 
New York 7, N. Y. 



.E. H. HANSEN 
L. B. ISAAC 

J. P. LlVADARY 
G. T. LORANCE 

J. A. MAURER 
W. C. MILLER 
K. F. MORGAN 



W. A. MUELLER 
HARRY RUBIN 
G. E. SAWYER 
S. P. SOLOW 
F. R. WILSON 
*E. C. ZRENNER 



STANDARDS. To survey the various fields or branches of the motion picture industry in an 
endeavor to bring before the Society any information on current or future practice or methods 
that would lead to possibilities of standardization of any specific procedure. 

F. T. BOWDITCH, Chairman 

Box 6087 
Cleveland 1, Ohio 



J. M. ANDREAS 
P. H. ARNOLD 
HERBERT BARNETT 
M. C. BATSEL 
M. R. BOYER 
F. E. CARLSON 
*T. H. CARPENTER 
E. K. CARVER 

H. B. CUTHBERTSON 

L. W. DAVEE 

J. A. DUBRAY 

A. F. EDOUART 



J. L. FORREST 
A. N. GOLDSMITH 
L. T. GOLDSMITH 
IRL GOSHAW 
HERBERT GRIFFIN 
A. C. HARDY 
D. B. JOY 
C. R. KEITH 
P. J. LARSEN 

R. G. LlNDERMAN 

C. L. LOOTENS 



J. A. MAURSR 

G. A. MITCHELL 

W. H. OFFENHAUSER, JR. 

G. F. RACKETT 

W. B. RAYTON 

HARRY RUBIN 

L. T. SACHTLEBEN 

OTTO SANDVIK 

LLOYD THOMPSON 

J. F. VAN LEUVEN 

H. E. WHITE 

A. G. ZIMMERMAN 



STUDIO LIGHTING. To survey the field of motion picture studio lighting in an endeavor 
to bring before the Society any information on current or future practice, and also to continually 
review this field for possibilities of standardization of any specific procedure. 



J. W. BOYLE 
H. J. CHANON 



C. W HANDLE Y, Chairman 

I960 West 84th St. 
Los Angeles 44, Calif. 

R. E. FARNHAM 



KARL FREUND 
W. W. LOZIER 



TECHNICAL NEWS. To survey the fields of production, distribution, and exhibition of 
motion pictures, and allied industries, to obtain technical news items for publication in the 
JOURNAL. 

A. C. BLANEY, Chairman 
1016 N. Sycamore St. 
Hollywood 38, Calif. 



J. W. BQYLB 
J. I. CRABTREE 

A. M. GUNDELFINGER 



C. W. HANDLEY 
EMERY HUSE 
H. R. LUBCKE 



K. F. MORGAN 

H. W. REMERSHIED 

WILLIAM THOMAS 



* Advisory Member. 



COMMITTEES OF THE SOCIETY 



TELEVISION. Technical consideration of the uses of motion picture television service; 
technical consideration of the phases of television which affect origination, transmission, dis- 
tribution, and reproduction of theater television. 



F. G. ALBIN 
R. B. AUSTRIAN 
R. L. CAMPBELL 
E. D. COOK 
C. E. DEAN 
A. N. GOLDSMITH 
T. T. GOLDSMITH 
HERBERT GRIFFIN 



P. C. GOLDMARK, Chairman 

485 Madison Ave. 
New York 22, N. Y. 

P. H. HISS 

C. F. HORSTMAN 

L. B. ISAAC 
A. G. JENSEN 
P. J. LARSEN 
C. C. LARSON 
NATHAN LEVINSON 
H. R. LUBCKE 



*I. G. MALOFF 
J. A. MAURER 
PIERRE MERTZ 

*PAUL RAIBOURN 
OTTO SANDVIK 
R. E. SHELBY 
E. I. SPONABLE 
H. E. WHITE 



TEST FILM QUALITY. To supervise the quality of prints of test films prepared by the 
Society. 

F. R. WILSON C. F. HORSTMAN 

THEATER ENGINEERING. The Committee on Theater Engineering comprises the 
membership of the four subcommittees listed below and is under the general chairmanship of 
DR. ALFRED N. GOLDSMITH, 597 Fifth Ave., New York 17, N. Y. 



Subcommittee on Film Projection Practice. To make recommendations and prepare specifi- 
cations for the operation, maintenance, and servicing of motion picture projection equipment, 
projection rooms, film storage facilities, and stage arrangements as they affect screen dimen- 
sions, placement, and the maintenance of loudspeakers. 

L. B. ISAAC, Chairman 
M. D. O'BRIEN, Secretary 
1540 Broadway 
New York 19, N. Y. 



HENRY ANDERSON 
T. C. BARROWS 
H. D. BEHR 
M. F. BENNETT 
KARL BRENKERT 
F. E. CAHILL, JR. 
C. C. DASH 
L. W. DAVEE 
A. S. DICKINSON 



J. K. ELDERKIN 
^ JAMES FRANK, JR. 
R. R. FRENCH 
E. R. GEIB 
ADOLPH GOODMAN 
HERBERT GRIFFIN 
SYLVAN HARRIS 
J. J, HOPKINS 
C. F. HORSTMAN 
I. JACOBSEN 



*J. H. LlTTENBERG 
E. R. MORIN 

J. R. PRATER , 
HARRY RUBIN 
J. J. SEFING 
R. O. WALKER 
V. A. WELMAN 
H. E. WHITE 
A. T. WILLIAMS 



Subcommittee on Television Projection Practice. To make recommendations and prepare 
specifications for the construction, installation, maintenance, and servicing of equipment for 
projecting television pictures in the theater, as well as the projection room arrangements neces- 
sary for such equipment, and such picture-dimensional and screen-characteristic matters as 
may be involved in theater television presentation. 

L. B. ISAAC, Chairman 
M. D. O'BRIEN, Secretary 

1540 Broadway 
New York 19, N. Y. 



F. G. ALBIN 

G. S. APPELGATE 
HERBERT BARNETT 
T. C. BARROWS 
M. F. BENNETT 

F. E. CAHILL, JR. 
L. W. DAVEE 
JAMES FRANK, JR. 

* Advisory Member. 



ADOLPH GOODMAN 
HERBERT GRIFFIN 
J. J. HOPKINS 
C. F. HORSTMAN 
C. R. KEITH 
J. J. KOHLER 
P. J. LARSEN 

*J. H. LlTTENBERG 

J. A. MAURER 



R. H. McCULLOUGH 

L. J. PATTON 
A. J. RADEMACHER 
HARRY RUBIN 
A. G. SMITH . 
E. I. SPONABLE 
* FRANK SUTTON 
V. A. WELMAN 



COMMITTEES OF THE SOCIETY 

Subcommittee on Screen Brightness. To make recommendations, prepare specifications 
and test methods for determining and standardizing the brightness of the motion picture screen 
image at various parts of the screen, and for specific means or devices in the projection room 
adapted to the control or improvement of screen brightness. 

F. E. CARLSON, Chairman 
Nela Park 
Cleveland 12, Ohio 

HERBERT BARNETT W. F. LITTLE C. M. TUTTLB 

E. R. GEIB W. B. RAYTON H. E. WHITE 

SYLVAN HARRIS A. T. WILLIAMS 

Subcommittee on Theater Engineering, Construction, and Operation. To deal with the 
technical methods and equipment of motion picture theaters in relation to their contribution for 
the physical comfort and safety of patrons so far as can be enhanced by correct theater design, 
construction, and operation of equipment. 

(Under organization) 



MEMBERS OF THE SOCIETY 

LOST IN THE SERVICE OF 

THEIR COUNTRY 



FRANKLIN C. GILBERT 



ISRAEL H. TILLES 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

Vol43 DECEMBER, 1944 No. 6 

CONTENTS 

PAGE 

Western Electric Recording System U. S. Naval 
Photographic Science Laboratory 

R. O. STROCK AND E. A. DICKINSON 379 

United States Naval Photographic Science Laboratories 

H. R. CLIFFORD 405 

Commercial Processing of 16-Mm Variable Area 

R. V. McKiE 414 

A Plan for Preserving 16-Mm Originals of Educational 
Films W. H. OFFENHAUSER, JR. 418 

Calcium Scums and Sludges in Photography 

R. W. HENN AND J. I. CRABTREE 420 

Society Announcements 442 

Index of the Journal, Vol 43 (July-December, 1944) : 

Author Index 448 

Classified Index 451 

(The Society is not responsible for statements of authors.) 

Contents of previous issues of the JOURNAL are indexed in the 
Industrial Arts Index available in public libraries. 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

HARRY SMITH, JR., EDITOR 

ARTHUR C. DOWNES, Chairman 

Board of Editors 

JOHN I. CRABTREE ALFRED N. GOLDSMITH EDWARD W. KELLOGG 
CLYDE R. KEITH ALAN M. GUNDELFINGER CHARLES W. HANDLEY 

ARTHUR C. HARDY 
Officers of the Society 
^President: HERBERT GRIFFIN, 

133 E. Santa Anita Ave., Burbank, Calif. 

* Past-President: EMERY HUSE, 

6706 Santa Monica Blvd., Hollywood, Calif. 
^Executive Vice-President: LOREN L. RYDER, 

5451 Marathon St., Hollywood, Calif. 
^^Engineering Vice-President: DONALD E. HYNDMAN, 

350 Madison Ave., New York, N. Y. 
*Editorial Vice-President: ARTHUR C. DOWNES, 

Box 6087, Cleveland, Ohio. 

** Financial Vice-President: ARTHUR S. DICKINSON, 
28 W. 44th St., New York, N. Y. 

* Convention Vice-President: WILLIAM C. KUNZMANN, 

Box 6087, Cleveland, Ohio. 
* Secretary: E. ALLAN WILLIFORD, 

30 E. 42d St., New York, N. Y. 
^Treasurer: M. R. BOYER 

350 Fifth Ave., New York, N. Y. 

Governors 

**FRANK E. CARLSON, Nela Park, Cleveland, Ohio. 
*|CHARLES W. HANDLEY, 1960 W. 84th St., Los Angeles, Calif. 
**EDWARD M. HONAN, 6601 Romaine St., Hollywood, Calif. 
"JCLYDE R. KEITH, 195 Broadway, New York, N. Y. 
**JOHN A. MAURER, 117 E. 24th St., New York, N. Y. 
*HOLLIS W. MOYSE, 6656 Santa Monica Blvd., Hollywood, Calif. 
*WILLIAM A. MUELLER, 4000 W. Olive Ave., Burbank, Cain*. 
*H. W. REMERSHIED, 716 N. La Brea St., Hollywood, Calif. 
**EARL I. SPONABLE, 460 W. 54th St., New York, N. Y. 
*JOSEPH H. SPRAY, 1277 E. 14th St., Brooklyn, N. Y. 
*REEVE O. STROCK, 111 Eighth Ave., New York, N. Y. 
**WALLACE V. WOLFE, 1016 N. Sycamore St., Hollywood, Calif. 

*Term expires December 31, 1944. 
**Term expires December 31, 1945. 
fChairman, Pacific Coast Section. 
jChairman, Atlantic Coast Section. 



Subscription to nonmembers, $8.00 per annum; to members, $5.00 per annum, included 

in their annual membership dues; single copies, $1.00. A discount on subscription or single 

copies 'of 15 per cent is allowed to accredited agencies. Order from the Society of Motion Picture 

Engineers, inc., Hotel Pennsylvania, New York 1, N. Y. Telephone No. PEnnsylvania 6-0620. 

Published monthly at Easton, Pa., by the Society of Motion Picture Engineers, Inc. 

Publication Office, 20th & Northampton Sts., Easton, Pa. 

General and Editorial Office, Hotel Pennsylvania, New York 1, N. Y. 

Entered as second-class matter January 15, 1930, at the Post Office at Easton, 

Pa., under the Act of March 3, 1879. Copyrighted, 1944, by the Society of Motion 

Picture Engineers. Inc. 



JOURNAL OF THE SOCIETY OF 
MOTION PICTURE ENGINEERS 

Vol 43 DECEMBER, 1944 No. 6 



WESTERN ELECTRIC RECORDING SYSTEM U. S. NAVAL 
PHOTOGRAPHIC SCIENCE LABORATORY* 



R. O. STROCK AND E. A. DICKINSON** 



Summary. This paper describes the complete 35-mmfilm and 33 l / t or 7<V rpnt 
disk recording and rerecording equipment installed for the U. S. Navy at the Photo- 
graphic Science Laboratory, Anacostia, D. C. Modern design excellent perfor- 
mance, and ease of operation are features of the installation. 



When Western Electric was called upon by the U. S. Navy, Bureau 
of Aeronautics, in the summer of 1942 to provide complete studio 
type of 35-mm recording equipment for the Photographic Science 
Laboratory, Anacostia, D. C., a considerable number of problems 
were presented immediately. During this period materials for fab- 
rication of equipment were very critical and, in addition, our stock of 
modern recording equipment was considerably depleted and could 
not be replaced without proper priority. 

It was required that we supply 2 complete studio channels, one 
recording and one rerecording channel, with the necessary acces- 
sories. The equipment was to be of the latest design and to embody 
all improvements of the recording art necessary for the production of 
high-quality sound training films for the U. S. Navy. Space and 
room layout had already been allocated for the Sound Division, in- 
cluding one main recording stage and one combination theater review 
room and rerecording monitor room. It was required that our equip- 
ment be installed within this area to provide the most efficient use of 
the designated space and to provide highest operating efficiency for 
the operating personnel. 

* Presented Apr. 18, 1944, at the Technical Conference in New York. 
** Electrical Research Products Division of Western Electric Co., Inc., New 
York. 

379 



380 



R. O. STROCK AND E. A. DICKINSON Vol 43. No. 6 




Dec., 1944 WESTERN ELECTRIC RECORDING SYSTEM 381 

From these requirements the problem was approached with 3 ob- 
jectives : 

(7) Engineering perfection. 

(2) Ease of operation and servicing. 

(3) Over-all appearance. 

% 

Since our stocks of standard equipment were low and much of the 
equipment to be supplied had to be designed and fabricated, it was 
felt that this was an excellent opportunity to embark on a new line 
of attack to comply with the above 3 objectives. Accordingly, a 
partial list of proposed requirements was drawn up as follows : 

(a) All equipment and controls associated with any particular activity should 
be incorporated in a "packaged" unit if possible. 

(6) All layouts and units in each channel should be identical to permit inter- 
changeability and easier training of the operating personnel. 

(c) Circuit changing to be done by switching wherever possible instead of by 
patch cords. 

(d) All standard circuits to be "normalled" through and to operate with a 
"dead" patch bay. 

(e) Mixer consoles to incorporate a level limiting amplifier as protection against 
overloads. 

(/) Rapid key switching of the mixer console outputs to either recording chan- 
nel. 

(g) Push-button equalizer switching into any input circuit of the mixer consoles. 

(h) Talk-back facilities between all locations. 

(i) Monitoring inputs, all at the same signal level, at any location from either 
channel. 

(j) All lines between rooms to be 600-ohm impedance. 

(k) Recording amplifier inputs to be high impedance for added flexibility. 

(/) Carrier- type noise reduction with reverse bias facilities. 

(m) Pre- and post-equalization with standard or push-pull track. 

() Light valve feedback amplifier to control the light valve resonant peak. 

(o) Stage playback unit completely self-contained to operate from any input 
source. 

(p~) Disk recording for 78 or 33 Vs rpm with reproducing facilities for either 
vertical or lateral disks. 

(q) Low level and high level test trunks between the recording rooms and all 
locations. 

(r) Provision to supply bus level to the 16-mm recording equipment. 

(s) Provide for utilization of output sources from 16-mm reproducers and non- 
sync turntables. 

(/) Adequate test equipment and accessories. 

A block diagram of the recording and rerecording facilities is shown 
in Fig. 1. A stage console for direct pickup is normally connected to 



382 



R. O. STROCK AND E. A. DICKINSON Vol 43, No. 6 




FIG. 2. Western Electric motor drive system. 




FIG. 3. Distributor and motor drive patch panel. 



Dec., 1944 WESTERN ELECTRIC RECORDING SYSTEM 383 

the recording channel bus, but by operating the console output key, 
the output is transferred to the rerecording channel. Similarly, the 
output of the rerecording console, which is normally connected to the 
rerecording channel, can be switched to the recording channel. A 
second mixer console, similar to the one on the stage, is shown in the 
scoring monitor room. Its output feeds trunks to both channels but 
is not normally connected to either. If it is desired to use it on either 
channel, this can be accomplished by making one patch on the input 
of the channel selected and throwing the output key on the console 
to the proper position. The stage and scoring monitor consoles are 
identical and can be used interchangeably. 

Microphones used are the RA-1142 directional cardioids and pickup 
trunks from either the stage or theater appear at the inputs of all 3 
consoles, making complete flexibility for utilization of live pickup 
positions. 

The outputs of four 35-mm rerecording reproducers "normal" into 
the rerecording console, but also appear at the scoring monitor con- 
sole. In addition, the 16-mm reproducers, reproducer turntables, 
scoring projector, and theater booth projector outputs can be patched 
into either the rerecording console or the scoring monitor console, 
giving complete input flexibility for rerecording if desired. 

Both recording channels are identical, each consisting of one 35-mm 
film recorder, one 78- or SSVa-rpm disk recorder, each with its asso- 
ciated amplifiers and control equipment, and the recording bus feed- 
ing the 16-mm recording equipment, which was furnished by J. A. 
Maurer, Inc. 

Headset and loudspeaker monitoring are provided on all consoles. 
Regular theater monitoring is normally used for rerecording by using 
the theater amplifier and horn system. If rerecording and mixing of 
voice scoring to the projected picture in the theater is desired, head- 
set monitoring is used with the horns disconnected to prevent feed- 
back. Headsets are used for stage pickup, but a loudspeaker is 
normally used in the scoring monitor room. Headsets are the 714-C 
receivers and loudspeakers are type 753-C. 

Flexibility of monitor selection has been accomplished very easily. 
Two monitoring busses, one for the recording and one for the re- 
recording channel, run to all locations, each bus consisting of 3 
monitoring sources from each channel, direct PEC and disk re- 
production. Each monitoring source is 600 ohms and its level has 
been adjusted to 30 dbm. Thus, we have 6 monitoring sources 



384 



R. O. STROCK AND E. A. DICKINSON Vol 43, No. 6 




Dec., 1944 WESTERN ELECTRIC RECORDING SYSTEM 



:5s;> 



appearing at all locations, each at 000 ohms and at the same signal 
level. At all locations a (i-position selector switch has been provided 
to select whichever monitoring source is desired and a high-impedance 
bridging amplifier feeds the monitor horns or receivers. It is thus 
possible to have all positions monitoring the same source, if desired, 




FIG. 5. Over-all view of rerecording console. 




FIG. 6. Operating control panels of rerecording console. 



or a different selection can be made at any location without affecting 
the others. These 6 monitoring positions and, in addition, the out- 
puts of the four 35-mm rerecorders, the theater projectors, and the 
scoring projector, also appear in the stage playback wall box. Thus, 
12 circuits are available on the stage in a selector switch to feed signal 
at 600 ohms and all at a level of 30 dbm to the portable playback 
unit. 



386 



R. O. STROCK AND E. A. DICKINSON Vol 43, No. 6 



Push-button talk-back selection is provided at each machine and 
on the mixer consoles, in addition to an interphone and a signal light 
system. This gives an adequate communication system between all 
locations, as well as promotes rapid and efficient production opera- 
tion. 

The standard Western Electric motor drive system is used. This 
consists of an accurate speed controlled d-c motor driving a distribu- 
tor, which in turn drives the 
individual recording, projec- 
tor, or camera motors. Four 
such distributor systems were 
furnished feeding into a dis- 
tributor and motor patch 
panel (Figs. 2 and 3). All 
motors and start circuits run 
directly to this panel where 
any combination of motors 
can be run from any selected 
distributor with the start 
position at any location. The 
starting of the recording sys- 
tem motors is normally con- 
fined to the recording machine 
position, but start positions 
have been provided at the re- 
recording-reproducers to per- 
mit rehearsals for recording 
without bothering the record- 
ing operators. Four separate 
start positions have also been provided in the theater booth to per- 
mit running a double film, continuous interlocked show if desired. 
Start positions also appear at the 16-mm equipment, the scoring pro- 
jector, and on the stage for the process projector and camera 
motors. 

An additional motor system feature has been included at the re- 
recording console control panel by providing a switch and field rheo- 
stat for manually controlling the speed of one distributor. By using 
one manually controlled variable speed distributor on one or more 
rerecording effect tracks many useful effects can be obtained. 

The rerecording mixer console is considerably more elaborate than 




FIG. 7. Turret panels are hinged for easy 
access and servicing. 



Dec., 1944 



WESTERN ELECTRIC RECORDING SYSTEM 



387 



the stage and scoring consoles, although each contains the same cir- 
cuit arrangements and operational features. A very desirable and 
useful feature for a rerecording mixer to be used particularly in the 




FIG. 8. Preamplifiers and other components are mounted 
in the trough which can be lowered for servicing. 




FIG. 9. Amplifier and channel components are contained in cabinet-type 

drawers. 

assembly of high-quality training films, is a sufficient number of 
equalizers with various characteristics that can be rapidly switched 
into and out of any input circuit. Six such equalizers have been in- 
cluded in this rerecording console and include 2 low-high equalizer- 
amplifiers (RA-1195), 2 telephone-radio effect equalizers, one com- 



388 



R. O. STROCK AND E. A. DICKINSON Vol 43, No. 6 




FIG. 10. Stage and scoring console. 




FIG. 11. Equipment may be serviced through 
panel doors on 5 sides of the console, two of which 
are shown. 



Dec., 1944 



WESTERN ELECTRIC RECORDING SYSTEM 



bination series of low-pass and high-pass filters, and one combination 
low-end and mid-range dialogue equalizer. 

The RA-1195 is a newly designed equalizer-amplifier combination 
which will raise or lower the low- or high-frequency end, either or 
both 15 db, at a constant 1000-cycle gain regardless of the adjustment 
of the equalizer. The 2 telephone-radio effect equalizers are variable 
effect units, each with its own adjustable output control. These are 
very useful in training film production in that each can be set for the 
effect desired and can be 
rapidly switched from one 
track to the other. 

A block schematic of the 
rerecording mixer is shown in 
Fig. 4. Four reproducer and 
2 microphone input positions 
are included. A group con- 
trol is a part of the reproducer 
mixer circuit and is useful for 
controlling the level of the 
combined effect and music 
tracks under the voice. A 
main gain control, pre- and 
post-equalizer facilities and a 
limiting amplifier feeding the 
recording bus complete the 
"program" circuit of the 
mixer. Mixer keys connect 
the pickup points directly to 
the mixer controls in the 
"down" position, or if thrown 
to the "up" position, connect the pickup points to an equalizer 
push-button selection bus which permits any equalizer to be placed 
in any input position. Direct monitoring is taken from the mixer 
console output through the monitoring selector switch, which can 
pick up any of the other monitoring points as described previously. 
The monitoring selector switch feeds the regular theater projector 
amplifier and horn system. By operating the console output key it 
may be connected to either the recording or rerecording channel. 

The level limiting amplifier (type 1126) is very useful to control 
peak overloads to the recording system and light valve. It has a flat 




FIG. 12. Operational controls mounted on 
hinged turret panel for easy access. 



390 



R. O. STROCK AND E. A. DICKINSON Vol 43, No. 6 




Dec., 1944 



WESTERN ELECTRIC RECORDING SYSTEM 



391 



frequency characteristic, a power-carrying capacity of +17.5 dbin, 
and a peak limiting ratio of 10 to 1 . This means that if the input level 
to the limiting amplifier is suddenly increased to 10 db above the 
level for which limiting is adjusted, the output level is increased by 
only one db and its action is instantaneous. Limiting level can be 
controlled in one-db steps up to 10 db. Recovery time is variable 
from 0.2 of a second to one 
second and its output distor- 
tion is less than one per cent 
for peak limiting of 5 db. 

Signal-to-noise ratio of 
the rerecording console is in 
excess of 60 db. 

The rerecording console 
embodies numerous con- 
structional and operational 
features not found in pre- 
vious units. An over-all 
view is shown in Fig. 5. Its 
over-all length is 15 ft in- 
cluding the 2 director-editor 
tables on each end. Space 
is provided for 2 mixer 
operators and 2 editors or 
directors at each end posi- 
tion. Small shielded fluo- 
rescent tubes are used for 
panel illumination. Because 
of its diffuse properties and 
the use of non-glare table 
top covering, very few shadows are cast on the operating panels with 
its attendant reduction in eye fatigue. 

The operating control panels are shown in Fig. 6. Two reproducer 
mixers, one microphone mixer, and one each of the equalizer controls 
have been placed on either end of the main control panel to permit 
one mixer operator to have the necessary controls within easy reach 
for small rerecording jobs. All controls are in turret panels arranged 
for easy access in operation. The turret panels are hinged, as shown 
in Fig. 7 for rapid and easy servicing. The preamplifiers and other 
components are mounted in the trough directly behind the main 




FIG. 14. Thirty-five millimeter film recording 
equipment. 



392 



R. O. STROCK AND E. A. DICKINSON 



Vol 43, No. 6 



panel. The trough can be lowered for servicing, as shown in Fig. 8. 
A similar mounting trough arrangement is used in both director's 
tables to mount the talk-back amplifier and the power unit. 

The amplifier and channel components are contained within the 
unit and are readily accessible for servicing, as shown in Fig. 9. Filing 




FIG. 15. 



All switches, meters, and other equipment are 
readily accessible on hinged panel. 



cabinet drawer construction is used and has proved very satisfactory. 
Low-level equipment is mounted in the left-hand drawer and the high- 
level equipment is mounted in the right-hand drawer, top units of 
both of which are hinged. Parallel talk-back microphone and selec- 
tor switches are also mounted in each director's table for added 
communication facilities to speed up operation. 



Dec., 1944 



WESTERN ELECTRIC RECORDING SYSTEM 



393 



A projected volume indicator using the VU meter and footage 
counter is placed directly below the screen for cuing and level in- 
dication. The footage counter is operated from an interlocked motor 
and can be reset by push-button control from the mixer position. 

The stage and scoring console is shown in Fig. 10 This unit is 
on castors, which are not shown in the photograph, and is moved 




FIG. 16. Disk recorder, table, and associated equipment, 
showing accessibility for servicing. 



easily. It is a completely self-contained unit, with a 4-position mixer 
used primarily for stage and microphone pickup but can also be used 
for small rerecording jobs. The same operational and technical 
features found in the larger rerecording console are also included in 
this unit. One low-high equalizer-amplifier (RA-1195), and 2 com- 
bination low-end and mid-range dialogue equalizers are supplied and 
connected for rapid push-button equalizer selection in the input cir- 
cuits. Since this unit is portable, connections are made to it by cords 
into plugs and jacks on the rear of the unit. These cords connect to 



394 



R. O. STROCK AND E. A. DICKINSON 



Vol 43, No. 6 



outlet boxes in the scoring monitor room and on the stage, and are 
identical permitting the 2 small consoles to be used interchangeably. 

The equipment units are mounted to be readily accessible for serv- 
icing on 5 sides of the console, two of which are shown in Fig. 11. All 
operational controls are mounted on the turret panel which tips 
forward for servicing, as shown in Fig. 12. The preamplifiers and 
associated equipment are mounted directly behind the panel in a 
trough arrangement, as can be readily seen from the photograph. 




FIG. 17. 



Four newly designed RA -1191 rerecording-reproducers mounted on 
tables, showing the associated loop rack. 



The amplifier and circuit schematic including the limiting amplifier 
is identical to the rerecording console, except that a monitoring power 
amplifier is included for driving a loudspeaker. In spite of the rela- 
tively confined space for the equipment the signal-to-noise ratio of 
this unit is in excess of 60 db. 

The consoles operate into 600-ohm lines which feed the recording 
bus on either of 2 channels. A block schematic of the recording and 
rerecording channels is shown in Fig. 13. This bus on either channel 
operates into one 35-mm film recording equipment, one 78 -or 33 Ya- 
rpm disk recording equipment, and one 16-mm film recording equip- 
ment. The film recording and disk recording equipment are mounted 



Dec., 1944 



WESTERN ELECTRIC RECORDING SYSTEM 



395 



in separate rack cabinets adjacent to the recording machines. As 
can be seen from the block diagram, a bridging amplifier (124-E) 
feeds the noise-reduction equipment (RA-1124) and the light valve 
feedback amplifier (RA-1111-A) which works into the light valve 
(RA-1061) in the film ^recorder (100-AA). The noise-reduction 
equipment is a carrier-type unit with reverse bias facilities. 

A VU type of volume in- 
dicator meter is mounted on 
both the film and disk racks 
and arranged to read either 
the incoming line level or the 
output of the bridging ampli- 
fier. Monitoring, direct 
PEC or disk, is fed to the 
selector switch mounted in 
the film rack for local moni- 
toring and also feeds the 
monitoring busses at the re- 
mote locations, as described 
previously. Local continuity 
monitoring is done by bridg- 
ing a high-impedance ampli- 
fier across whichever position 
is selected and driving local 
speaker units mounted above 
each recorder. The power 
supplies. for the film and disk 
equipment are all mounted 
in the power room, but are 
remotely controlled from 
each rack. 

An identical bridging am- 
plifier feeds the lateral disk 
recording machine (D-85249] which has been modified to cut either 
78- or SSYs-rpm disks. Recording is normally made on acetate disks, 
and reproduction from these disks is accomplished with a 9-A repro- 
ducer pickup and associated equalizers. 

The film and disk recording equipments on both channels are 
identical both as to components and rack layouts. 

A view of the 35-mm film recording equipment is shown in Fig. 14. 




FIG. 18. 



Full view of reproducer and 
mounting table. 



396 



R. O. STROCK AND E. A. DICKINSON Vol 43, No. 




Dec., 1944 WESTERN ELECTRIC RECORDING SYSTEM 397 

The amplifiers are of the vertical chassis type and by removal of the 
front panel all wiring is exposed, facilitating rapid servicing. The 
rack cabinets are completely enclosed and provided with adequate 
ventilation. 

The 35-mni film recorder is the 100-AA, which uses an RA-1061 




FIG. 20. Portable test unit. 

2-ribbon or 4-ribbon light valve to record either 100-mil standard or 
push-pull sound track. 

The recorder mounting table follows the same general lines of con- 
struction as the recorders and the consoles. Talk-back selection and 
talk-back speaker, motor system start switches with speed indicating 
meter, and signal system are mounted on a sloping panel immediately 
below the table top which, combined with the controls on the re- 
corder, puts all the operating controls within easy reach. This con- 
trol panel hinges for servicing, as shown in Fig. 15. Space is pro- 



398 



R. O. STROCK AND E. A. DICKINSON Vol 43, No. 6 





vided in the table for film magazine and equipment storage. Door 
switches operate tubular lights for interior illumination when the 

doors are open. A recess is provided 
at the floor level for "toe" room for 
the operators. Vertical barriers are 
placed inside the rear panel to provide 
channels for segregation of the differ- 
ent service wiring brought up from the 
m^ conduit ducts into the recorder unit. 

The disk recorder, recorder table, 
and associated equipment are shown 
in Fig. 16. The same design and con- 
struction are followed in this unit and 
servicing is accomplished easily. 

-TheRA-1191 rerecording-reproducer 
is a newly designed 35-mm film repro- 
ducer for rerecording. Its exterior ap- 
pearance was made to conform to the 
general design of the rest of the equip- 
ment supplied. A photograph of four 
of these reproducers and their mount- 
ing tables with the associated loop rack 
is shown in Fig. 17. These RA-1191 
reproducers reproduce 100-mil stand- 
ard and 100- and 200-mil push-pull 
sound track. A view of the repro- 
ducer and its mounting table is shown 
in Fig. 18. Here, again, the controls 
are mounted on a sloping panel for 
convenience in operating and which, 
as in the other tables, is hinged for 
ease in servicing. 

The height of the reproducer, as 
well as the recorder tables, has been 
adjusted to cause a minimum of 
operating fatigue to the personnel. 
Space has been provided for reel stor- 
age in both the front and rear of the table. The end legs of the tables 
are hollow and equipped with barriers for circuit segregation through 
which all wiring is brought into the machine controls from the 




FIG. 21. Test trunk rack. 



Dec., 1944 



WESTERN ELECTRIC RECORDING SYSTEM 



399 



duct beneath. The end panels are removable for ease in installation. 

A block schematic of the rerecording reproducer system is shown 
in Fig. 19. All 4 circuits are identical and include a booster amplifier, 
a post-equalizer which may be switched in the reproducer circuit by 
a key, a variable film loss equalizer, and an output attenuator. The 
outputs of the 4 reproducers normal to the rerecording console. The 
power units are located in the power room and are remotely controlled 
from the rerecorder equipment rack. Monitor facilities from the 
monitoring bus and talk-back 
are also provided. 

A portable test unit equipped 
with casters, shown in Fig. 20, 
can be easily moved to any 
location for testing, but is 
normally located in the re- 
cording room. As can be seen 
in the photographs, it contains 
an oscillator, gain set, vacuum 
tube test meter, and a volt- 
ohmyst. Patching and test 
terminations are also included. 
Space is provided for equip- 
ment storage and kneehole 
room added for additional 
ease in using. 

Two pairs of low-level and 
2 pairs of high-level test cir- 
cuits run to every location and 
terminate in the recording 
room in a test trunk rack, 
shown in Fig. 21. Normally 
all routine testing can be done from this position since the portable 
test unit is located in the recording room adjacent to this rack, but 
for other test work the portable unit can be easily moved. Since 4 
pairs of circuits run to every location, special circuit setups can be 
accomplished by merely cross-patching in the test rack, which greatly 
adds to the flexibility of the whole installation. A-c and d-c test 
voltages are also available on this rack for added testing convenience. 

A portable stage playback unit is shown in Fig. 22. This unit is 
self-contained and uses a high-impedance amplifier for bridging across 




FIG. 22. Portable stage playback unit. 



400 



R. O. STROCK AND E. A. DICKINSON 



Vol 43, No. 6 



the 600-ohm monitoring bus. The input circuits feeding the unit are 
all at 30 dbm level and sufficient gain is provided to drive the loud- 
speaker reproduction at 20 w. The input plugs into a selector switch 
on the stage wall where 12 different pickup sources can be used. 
Headphone jacks are provided on the unit so it may be used for pre- 
or post-scoring. Accessibility to equipment in the unit is shown in 
Fig. 23. 




FIG. 23. All equipment is easily accessible. 



Two very useful accessories are the light-valve projector and the 
light- valve stroboscope (RA-1196). The projector is shown in Fig. 
24. The light valve is mounted on the inspection table, and a beam 
of light projected through the ribbons passes through a lens system 
and prism which forms an enlarged image of the ribbons on a 4V2-m. 
light-shielded screen. Signal and d-c are fed into the light- valve 
ribbons, and the ribbon action can be observed on the screen. Ribbon 
unbalance, grounds, ribbon bowing, and foreign matter can be easily 



Dec., 1944 



WESTERN ELECTRIC RECORDING SYSTEM 



401 



and quickly detected. For case in use, this instrument has been 
mounted at eye level in the test trunk rack. 

The light-valve stroboscope (RA-1196) is shown in Fig. 25. This 
unit consists of a microscope designed to mount on the light valve in 
the recording machine in such manner that a magnified image of the 




FIG. 24. 



Light-valve projector, showing ribbon image on 
rear screen. 



ribbons is produced in the eyepiece of the microscope. A stroboscope 
disk operated by a small variable-speed motor interrupts the light 
beam. The speed is variable over a considerable range so that when 
frequencies of from 50 to 15,000 cycles are applied to the light valve 
they appear to be "stopped" in motion and their behavior may be ob- 
served and studied. The motor normally operates from 115 v a-c, 
but if frequencies below 50 cycles are to be observed the voltage may 



402 



R. O. STROCK AND E. A. DICKINSON Vol 43, No. 6 




FIG. 25. Light-valve stroboscope. 




FIG. 26. Light-valve stroboscope mounted for use on the 100-AA 
film recorder. 



Dec., 1944 WESTERN ELECTRIC RECORDING SYSTEM 



403 




FIG. 27. 



Sound equipment in U. S. Naval Photographic Science 
Laboratory, Anacostia, D. C. 




FIG. 28. 



Sound equipment in U. S. Naval Photographic Science 
Laboratory, Anacostia, D. C. 



404 R. O. STROCK AND E. A. DICKINSON 

be lowered by a Variac or other means and the ribbon action at the 
lower frequencies studied. 

The speed of the stroboscope disk light beam interrupter is varied 
by changing the amount of magnetic drag applied to an aluminum 
cup attached to the motor shaft at the opposite end from the inter- 
rupter disk. A permanent magnet is mounted on a movable shaft 
so that it just clears the contour of the aluminum cup. When the 
magnet is moved in or out of the aluminum cup varying amounts of 
eddy current drag are exerted which varies the speed of the motor. 
This damping force tends to stabilize the motor driving the interrupter 
disk and prevents "hunting" or "drifting" which occurs with the usual 
voltage control. A photograph of the unit in use on the 100- A A film 
recorder is shown in Fig. 26. This unit supplies a long-felt need for 
an instrument which is easy and rapid 'to use for observing the action 
of the light valve ribbons in operation on the recording machine at 
any frequency. 

Views of the sound equipment in the completed installation are 
shown in Figs. 27 and 28. 

The system as herein described fulfills the primary objectives 
originally set up. The recording system has a normally flat frequency 
characteristic from the microphone to the light valve, an adequate 
factor of safety for overload, slightly less than 1 Y 2 per cent over-all 
harmonic distortion, and a signal-to-noise ratio in excess of 60 db. 
The equipment layout provides a high degree of flexibility and rapid, 
efficient operation with a minimum amount of time required for train- 
ing of operating personnel. A departure has been made from previous 
concepts of constructional design to facilitate ease of operation and 
servicing of the equipment. It presents a pleasing appearance which 
materially aids, psychologically, the production of high-quality 
training films. 

Some of the equipment referred to in this paper has been covered 
fully in previous technical papers before the Society. It is planned 
to describe in more detail, at later meetings of the Society, the techni- 
cal features of the apparatus designed especially for this project. 

We want to take this opportunity to thank Commander Thorne 
Donnelley, Lt. George Carrol, Lt. Franklin Hansen, and their staffs 
for their cordial help and cooperation, and their suggestions during 
the design, fabrication, and installation of the equipment. 



UNITED STATES NAVAL PHOTOGRAPHIC 
SCIENCE LABORATORIES* 



HELEN R. CLIFFORD** 

Summary. This paper is the narration to a sound slide film introducing the 
Navy's new laboratory at Anacostia, D. C. (construction completed December, 1943). 
It gives a brief history of military photography leading to the Navy's need for its own 
laboratory for secret and confidential projects, discusses military organization, gives 
a tour of the laboratory, presenting especially the work of divisions concerned with 
motion picture production, still photography, aerial photography, graphic arts and 
photolithography, and sketches the services which the laboratory performs for all 
ships and stations. 

American wars were the first wars in history to be recorded by 
photography. Although a few daguerreotypes were made of the 
leaders in the Mexican War, it was by the photographs of William 
Brady that the Civil War was promptly reported to the civilian 
population. By the time of the Spanish- American War the infant 
motion picture process was used to report the activities of Theodore 
Roosevelt and his Rough Riders. Aerial reconnaissance from planes 
was essayed during World War I. Thus it was that photography 
became associated with aviation, even though the Navy had not 
yet officially recognized its importance. The first photographers 
ratings were not issued until 1920; prior to that time Naval photog- 
raphers had been variously rated as ship's cooks, pharmacist's mates, 
gunners and aviation printers. 

In the period between World War I and World War II, both the 
quality and the quantity o/ photography grew by leaps and bounds. 
By its commercial use, for both entertainment and journalism, it 
became one of the most important media of modern communication. 
During this period Naval photographers were experimenting with 
aerial geodetic mapping for the Hydrographic Office, vertical and 
oblique photography for the Departments of Commerce, Interior, 
and Agriculture, and aerial reports on fleet firing and aircraft bombing. 

* Presented Apr. 18, 1944, at the Technical Conference in New York. 
** Lieutenant (j.g.), W-V(S), USNR, U. S. Naval Air Station, Anacostia, D. C. 

405 



406 



H. R. CLIFFORD 



Vol 43, No. 6 



As the war clouds again gathered over Europe, the importance of 
photography in mechanized and psychological warfare became in- 
creasingly apparent; so the Secretary of the United States Navy 
convened a board to review the Navy's photographic facilities and 
to make recommendations for its needs. Several months before the 
Japanese attack upon Pearl Harbor, this board presented its recom- 
mendations, which included expansion of existing facilities under the 
cognizance of the Bureau of Aeronautics, and construction of a 
laboratory fully equipped to supply the Navy's every photographic 
need, particularly upon secret projects. 






Official U. S. Navy Photograph 
FIG. 1. Photographic Science Laboratory, Naval Air Station, Anacostia, D. C. 

Construction of the Photographic Science Laboratory was begun 
in February, 1942. The Bureau of Yards and Docks supervised the 
planning and construction of the building; the Eastman Kodak 
Company provided architectural, engineering, and equipment-pro- 
curing services; the Bureau of Aeronautics was technical adviser to 
co-ordinate and approve plans. In December, 1943, the modernistic 
building on the grounds of the Naval Air Station at Anacostia, D. C., 
was completed (Fig. 1). Its personnel is composed of highly specia 1 - 
ized technicians, artists, and administrators who have been trained 
to maintain Naval security. About one-fourth of the ship's com- 



Dec., 1944 U. S. NAVAL PHOTOGRAPHIC LABORATORIES 407 

pany is composed of members of the Women's Reserve. Military 
duties taking precedence over photographic projects may be assigned 
to anyone. Members of the Women's Reserve have their own 
watches, comparable to those of the men. 

By authority of the Commanding Officer of the Naval Air Station, 
Marine guards challenge all persons entering or leaving the grounds. 
Upon entering the building authorized visitors identify themselves 
to the Duty Officer. They move through the air-conditioned, 
fluorescent lighted passageways under escort, and are admitted only 
to the areas where they have particular business. 

Commander Thorne Donnelley, USNR, Officer in Charge of the 
Photographic Science Laboratory, is responsible to the Chief of the 
Bureau of Aeronautics via two commands: For administrative 
procedures and military security via the Commanding Officer of the 
Naval Air Station ; for functional and productive procedures via the 
Director of Photography, Bureau of Aeronautics. 

The organization under administration consists of a number of 
divisions, directed by division officers. Any division may request 
the work of any other division; but the services of Personnel Divi- 
sion, Supply Division, Ship Service, Engineering and Maintenance 
Division, and Technical Developments Division are directed spe- 
cifically to providing efficient operational conditions for all. 

The Personnel Division has helped procure the highly technical 
staff. With camera crews and students of the Motion Picture 
Camera School and the Photolithography School (both offering 
advanced training to graduates of the Navy's School of Photography 
at Pensacola, Florida) constantly coming and going, this division 
does a volume business in writing temporary duty orders and arrang- 
ing transportation to all parts of the world. 

The Supply Division procures materials for photographic produc- 
tions : Film in cases, chemicals in kegs, other equipment in carloads 
difficult as they now are to obtain. In its stock rooms are kept the 
materials necessary to operate the laboratory for a period of 3 to 
6 months. This division also outfits all the Navy's advance base 
photographic interpretation units. 

By providing wholesome, appetizing food, Ship Service helps to 
keep the ship's company in good spirits. 

The Engineering and Maintenance Division has facilities which 
include a carpenter shop, a machine shop, a precision shop, and 
temperature chambers for checking aerial cameras under arctic and 



408 H. R. CLIFFORD Vol 43, No. 6 

tropical conditions. In addition to repairing and maintaining 
specialized photographic gear, this division constructs miniatures 
and models and provides the mechanical and electrical services 
necessary for the efficient operation of the sound stage. 

It has been said that within the Technical Developments Division 
occurs the science that spells the laboratory's middle name. This 
division works constantly for the advancement of photography by 
standardizing processes, solving problems, adapting mechanisms or 
inventing new ones as needed. It prepares all photographic solutions 
used within the laboratory and distributes processing instructions 
to combat units. At its optical testing bench, lenses are evaluated 
for focal length, centering, aberrations, run-off, and definition by 
examining an image of an artificial star produced at the end of a 
275-ft collimating tube. Other activities of this division include 
photomicrography, microscopy, and photometry. 

Since the laboratory is a service facility for the entire Navy, it 
receives requests for motion pictures to be produced, for still photog- 
raphy to be processed, enlarged, and copied, for aerial equipment to 
be distributed to the fleet, for aerial photographs to be corrected for 
distortion and aerial mosaics to be made, for photographic services 
for the Office of Public Relations, for photolithographic services, and 
for a wide variety of other needs. 

Requests for photographic services are addressed to the Director 
of Photography, Bureau of Aeronautics. If approved, they are 
forwarded to the Officer in Charge, Photographic Science Laboratory. 
From his office they are turned over to Operations which is really 
the "nerve center" of the entire organization. By Operations the 
work is allocated to the divisions concerned. 

A large part of the work orders which are received calls for the 
production of motion pictures for which the activities of a number 
of divisions are needed: Writers and Directors Division, Motion 
Picture Photography Division, Motion Picture Processing Division, 
Editorial Division, Art and Animation Division, Music Division, 
and Sound Division. 

Writers and Directors Division provides the ideas through which 
the best psychological and pedagogical principles are combined with 
originality of treatment. Different techniques are employed in the 
preparation of scripts for industrial incentive films, recruiting films, 
training films, and reporting films. A procedure has been developed 
whereby the script is generally submitted to the requesting agent at 



Dec., 1944 U. S. NAVAL PHOTOGRAPHIC LABORATORIES 



409 



three stages of development. After an initial conference in which 
the needs to be met by the motion picture are discussed, a preliminary 
outline is prepared. Later an action outline is submitted; and 
finally, a master shooting script is prepared, with storyboard attached 
if necessary. The requesting agent supplies a technical adviser who 
is responsible for the technical accuracy of the film. At each stage 
of script preparation, written approvals are obtained so that complete 
satisfaction with the finished product will be assured. 




Official U. S. Navy Photograph 

FIG. 2. On the stage cameras photograph action within a Navy plane set, 
while the sound recording is controlled from booth on the second deck. 



When the master shooting script bears written approvals, for 
content by the technical representatives of the requesting authority, 
for form by the Division Officer of Writers and Directors Division, 
a 16-mm or 35-mm camera crew is assigned and equipment is issued 
by the Motion Picture Photography Division. The camera crews 
work under varied conditions, on the land, in the air, on the sea, and 
under the sea. Their assignments may take them to Naval activities 
near to Anacostia, or they may accompany the fleet to its advance 



410 



H. R. CLIFFORD 



Vol 43, No. 6 



depots or into combat areas. When feasible, productions are made 
on the sound stage at the laboratory (Fig. 2) . There, the sets usually 
represent military locales: for example, the bridge of a ship, the 
interior of a patrol bomber, engine rooms, fire-control stations, or 
radio rooms. The facilities of the sound stage include completely 
modern electrical and lighting equipment, grip equipment, and back- 
ground projection equipment. In line with Navy construction the 
catwalks are of metal rather than wood. 




Official U. S. Navy Photograph 

FIG. 3. Three of the 6 continuous drying cabinets in the Motion Picture 
Processing Division. From loading to final take-off, the film travels 7000 ft 
or 1.3 miles. 



Three shifts "daily in the Motion Picture Processing Division 
develop and print the footage which the camera crews turn in, 
whether 16-mm or 35-mm, black-and-white or Kodachrome, and 
sound film of both variable area and variable density (Fig. 3). In 
addition to processing film for motion pictures in production, this 
division also processes a large percentage of the combat footage 
flown in from the fleet to the Navy Department. 

To each director of a motion picture, a cutter is assigned by the 
Editorial Division. When it is necessary to cut in stock shots, such 



Dec., 1944 U. S. NAVAL PHOTOGRAPHIC LABORATORIES 411 

as those of disasters, foreign craft, or historic combat, the files of the 
Film Library are consulted. Editorial Division is responsible for 
approximately twenty stages of film handling from the completion 
of photography to the delivery of the first composite print to the 
requesting authority. It is charged with the storage of all negative 
film, both still and motion picture, for the United States Navy. 
The vaults in which nitrate film is stowed are constructed with 
explosion hatches. 

Simultaneously with the shooting, processing, and rough cutting 
of the motion picture, animation is being prepared as needed. Ani- 
mated diagrams, teaching the operation of secret new Naval equip- 
ment, are recorded by the specially constructed animation camera. 
In addition to the work supplied for motion pictures, the Art and 
Animation Division produces slide films, supplies titles, designs 
insignia, creates art work for books and posters, and at times and 
perhaps most important of all, diagrams action which assists in the 
development or protection of combat tactics. 

If necessary, original music, suited to the mood and tempo of any 
motion picture, is provided by the Music Division. A library of 
stock music is being accumulated by making recordings of the United 
States Navy symphonic band. 

The Sound Division is completely equipped for all recording needs, 
either fixed or portable. The former includes facilities to rerecord 
six 35-mm, three 16-mm, and 2 disk sound tracks simultaneously; 
the latter includes portable production channels and newsreel-type 
recorders for both 16-mm and 35-mm. A theater with specially 
designed acoustical construction and with seating capacity for 50 is 
used as a rerecording chamber and for acceptance screenings. 
. After the sound has been recorded and an interlock screening has 
been held, the composite print is made and the original requesting 
authority is invited to an acceptance screening. 

In addition to requests for motion pictures, many calls are also 
received by Operations for the services of the Graphic Arts, Still 
Photography, and Aerial Photography Divisions. 

The facilities of the Still Photography Division include a wide 
variety of cameras, developing tanks, washers, driers, trimmers, 
enlargers, and printers. Photomurals, microphotography, and color 
photography are some of the specialized activities. Thousands of 
contact prints and enlargements are made for the Navy Department, 
frequently of pictures taken in sorties over combat areas. A supply 



412 H. R. CLIFFORD Vol 43, No. 6 

of prints is delivered at frequent intervals to the Photographic 
Interpretation Center for strategical information. 

The Graphic Arts Division provides mimeographing and photo- 
static services. On its monotype process camera, negatives up to 
20 X 24 in. can be made. This division makes 300-line screen repro- 
ductions which are run off on Harris offset presses at the rate of 
about 4500 impressions per hr. It prints and binds booklets for 
distributing tactical information to the fleet and other operational 
units. 

Last but not least, is the Aerial Photography Division. It checks 
all aerial cameras and specialized equipment supplied to the Navy's 
widely separated ships and stations. Its -laboratory section makes 
ratio prints from aerial photographs and large negatives. This 
division also tests photographic installations in aircraft, experiments 
with aero-Kodacolor which can be processed in the field, compiles 
maps from aerial photographs and makes aerial mosaics. 



This hasty tour of the Photographic Science Laboratory has shown 
that it is a photographic service center for the United States Navy, 
especially for assignments of a secret or confidential nature that 
should be handled only by Naval personnel. 

Upon request approved by the Bureau of Aeronautics, Director 
of Photography, it produces motion pictures on the sound stage or 
on location. When advisable, motion picture units are sent outside 
the United States to record tactics used by the fleet or by land-based 
Naval forces. These films vary in content and treatment. Incen- 
tive films may increase industrial production or aid recruiting pro- 
grams. Training films may teach Naval organization, customs, and 
specialized techniques to the ''boot," or they may instruct officers 
and mates of many years' experience in the use of secret ordnance or 
new detection devices. Report films may record Naval action on 
the high seas, or may serve research upon cures to be effected or 
new mechanisms to be perfected. 

To Navy photographers with the fleet or at advanced bases, the 
laboratory sends equipment and film as well as processing instruc- 
tions suited to various climatic conditions. With the information 
supplied by specially trained photographers using cameras shipped 
from Anacostia, invasion strategy is planned. For the footage 
exposed in these advanced areas and flown back by Naval Air Trans- 



Dec., 1944 U. S. NAVAL PHOTOGRAPHIC LABORATORIES 413 

port Service, there are processing and copying services available at 
home. 

Whatever job, large or small, is assigned to this shore establish- 
ment, it is the function of its personnel to carry through as quickly 
as possible for the most efficient operation of the United States Fleet. 



COMMERCIAL PROCESSING OF 16-MM 
VARIABLE AREA* 

ROBERT V. McKIE** 

Summary. This paper presents a series of curves showing the tolerance for 
commercial processing of 16-mm variable-area sound tracks. Values of distortion 
encountered in commercial practice are indicated. 

The problems of processing control for 16-mm film are basically the 
same as the problems of processing control for 35-mm film. The 
processing control of 35-mm variable-area sound track has been suc- 
cessfully established by the cross-modulation method. 1 This method 
was also adopted to establish the processing tolerances for variable- 
area track on 16-mm. It has taken us many years to establish 
adequate controls for 35-mm film and many improvements in develop- 
ing, printing equipment, and technique have been necessary. Labora- 
tory equipment for 16-mm has not kept pace with the improvements 
in 35-mm equipment, hence we found more difficulty with 16-mm 
processing at this time than we now experience with 35-mm process- 
ing. 

Nevertheless, the increased activity in the 16-mm field makes it 
necessary to establish commercial processing tolerances for 16-mm 
film. This increased activity results from the fact that the greater 
part of the pictures boing produced by Hollywood studios is re- 
duced to 16-mm for war activities, either by rerecording or by the 
photographic process. 

These pictures are distributed to the Army and Navy for pro- 
jection at various camps overseas. From 65 to 75 composite prints 
are made on each picture and, including the many training films being 
produced at this time, the total 16-mm film being processed will aver- 
age millions of feet per month. 

Two types of measurements were desired. First, measurements 
to determine processing controls and, second, measurements of dis- 
tortion on 16-mm sound track properly processed. 

* Presented Apr. 19, 1944, at the Technical Conference in New York. 
** RCA Victor Division of Radio Corporation of America, Hollywood. 
414 



PROCESSING OF 16-MM VARIABLE AREA 



415 



400^ 



OO CYC .ES CR( S3 MO XJLAT 



A "family" of 16-mm negatives was recorded at 80 per cent ampli- 
tude, each negative consisting of (1) 400 cycles for reference level, 
(2) 4000 cycles for measuring high-frequency loss, and (3) 4000 cycles 
modulated in amplitude at a 400-cycle rate for cross-modulation 
measurements. The 400-cycle section of the test was used to obtain 
the data for the distortion measurements. 

Using a Corning 584 filter, EK 5372 fine-grain recording stock was 
exposed as a negative material over a density range from 1.80 to 2.15. 
This negative was developed at a pre-established speed for variable- 
area sound track negative deter- 
mined by a series of exposure 
tests in a print-type developer. 
A family of contact prints was 
then exposed with unfiltered 
mercury-vapor light covering a 
density range from 1.00 to 1.40 
using EK 5302 as a positive 
material. 

A review of the quality of 
recording equipment showed that 
even a better than average com- 
mercial 16-mm reproducer would 
be unsatisfactory for measuring 
these tests. Accordingly, a 
special 16-mm reproducer of the 
"grindstone" type was set up 

and used for the measurements F . 

subsequently discussed. The 

tests were measured through the special film measuring channel by 
running the film in the form of a loop. 

Fig. 1 shows the cross-modulation curves plotted against print 
density. It has been established by numerous frequency tests and 
by practical experience with music and dialogue recordings that 30- 
db cancellation of the 400-cycle component in the cross-modulation 
test is satisfactory for all types of material, and density tolerances 
have been established at this value. From Fig. 1 the print density 
tolerance for a negative density of 2.15 is 0.92 to 1.42. 

However, experience has proved that owing to variations in ex- 
posures and emulsions it is more practical to maintain the print 
density within the smallest possible tolerance, and to allow the max- 



\ 



\/ 



416 



R. V. McKm 



Vol 43, No. 6 



16 MM PROCESSING TOLERANCE 



imum variations in negative density. All laboratories now have a 
well-established control department, and tests covering the entire 
process are made at definite intervals so that the variations which do 
occur can be controlled easier in the laboratory than during actual 
production, where the sound tracks are recorded under varying con- 
ditions of temperature that may effect the emulsion and cause 
changes in the density of the sound track negative. 

This method of maintaining the print density within the smallest 
possible tolerance and allowing the maximum variations in negative 

density, requires the least num- 
ber of timing corrections. Nega- 
tive densities can easily be main- 
tained within the wide tolerances 
permissible for a given optimum 
print density under reasonable 
processing conditions. This 
method eliminates unnecessary 
handling and timing of each 
scene of the negative when sent 
to the laboratory, or the neces- 
sity of keeping elaborate records 
on the density of each scene. 
Only negative variations, which 
do not fall within the wide 
negative tolerance as indicated 
by the cross-modulation test, 



FIG. 2. 



need be noted. 

Fig. 2 shows density tolerances 
for a combination of negatives and prints having 30-db cancellation 
and indicates a negative density range of 1.92 to 2.45 for an opti- 
mum print density of 1.20 =*= 0.10. 

The 400-cycle section of the test recording was used for distortion 
measurements. The grindstone was used as a means of running this 
film. For any given negative or print density covered by the density 
range, as indicated above, the distortion measured from 2.5 per cent 
to 3.5 per cent using a General Radio distortion factor meter. 

Under adequate control the sound quality depends largely upon 
the mechanical performance of the printer and, to some extent, upon 
the type of developer used by the laboratory. 

The processing conditions under which these tests were made 



Dec., 1944 PROCESSING OF 16-MM VARIABLE AREA 417 

represent commercial practice and may not represent the optimum 
conditions for processing 16-mm film. They do, however, represent 
the average and the distortion figures as indicated in this paper, even 
though they may not represent the absolute minimum, appear to be 
about the right order of magnitude for the average commercial re- 
cording. 

It should be remembered that the distortion figures include the 
distortion of the recording and reproducing systems, as well as the 
distortion of the film itself. We do not know of any satisfactory 
method for separating these distortions. Under existing circum- 
stances, we do not consider this magnitude presents a serious problem. 

REFERENCE 

1 BAKER, J. O., AND ROBINSON, D. H.: "Modulated High-Frequency Record- 
ing as a Means of Determining Conditions for Optimal Processing," J. Soc. Mot. 
Pid. Eng., XXX (Jan., 1938), p. 3. 



A PLAN FOR PRESERVING 16-MM ORIGINALS OF EDUCA- 
TIONAL FILMS* 

WM. H. OFFENHAUSER, Jr.** 

Summary. The growth of 16-mm release print volume has been so rapid as a 
result of the war that there is serious danger of the destruction of priceless originals if 
the present haphazard methods of supervision of print manufacture are continued. 
The situation has already become acute in 16-mm Kodachrome. 

The solution appears to rest in anticipating print needs and in purposefully pre- 
serving originals by dead storage under suitable refrigeration. To accomplish pres- 
ervation, it is necessary that all release prints be made from intermediate copies made 
specifically for the purpose. In this manner, it is possible to keep the originals in 
storage for a relatively long time, removing them periodically for the sole purpose of 
making intermediate copies, such as dupes, but in no case using them for making 
release prints. A cycle of 51 weeks of storage and one week of use is suggested as a 
starting point. 

With the recommended procedure and with present-day materials under good con- 
trol in duplicating, upward of 2500 release prints can be made from a single original. 
This large number is by no means the maximum, as the number of copies that can 
be produced in each step can be materially increased with care in handling. The 
method is applicable to the making of black-and-white prints from Kodachrome and 
similar originals, as well as to color prints. In the broader aspect it may be applied 
to the preservation of educational films however made. 

It has been said that the maturity of an age can be judged quickly 
by the amount of recorded material that is purposefully preserved 
for a future time. If today we look forward a generation, let us say, 
and review what we are now doing, we find that we are at the begin- 
ning of a new era in motion picture history: an era of purposefully 
recording in films the ideas that we wish to convey to others of our 
own generation and to generations to come. Our civilization is 
"coming of age." 

There has been much talk lately of post-war planning; the planning 
of individuals, the planning of governments and nations, the planning 
of social groups, the planning of industry, and the planning of educa- 
tion. Hollywood is doing its share of planning; planning not only 

* Presented Apr. 19, 1944, at the Technical Conference in New York. 
** New York, N. Y. 

418 



PRESERVING ORIGINALS OF EDUCATIONAL FILMS 419 

for bigger and better entertainment films, but also helping in the 
standardization of 16-mm equipment and materials now required by 
the Armed Forces. Much planning is still in the formative stage; 
most of it has not materialized so far into plans that concern them- 
selves with the physical materials and their preservation. 

The motion picture has proved a most effective teaching aid in the 
present war. It is in very wide use and has been especially valuable 
in reducing the amount of time required by a student to acquire a 
particular quanta of information and, in the case of equipment, a 
particular degree of skill. All who have observed it in action agree 
that the motion picture can serve an even more useful purpose in the 
post-war period. This paper will be limited in scope to 16-mm films 
whose primary purpose is education in the broader aspect. 

Present Status. If material is to be preserved, there must be a 
plan to accomplish the preservation. At this time we are so en- 
grossed with the job of "getting the war over" that we have given 
little thought to what we shall do with the material being currently 
produced. The thought has been expressed, "We'll worry about 
that when the time comes," to which the reply is made, "You won't 
have to worry about it ; the originals and the duplicates are in such 
bad condition now, that there won't be anything left to worry about 
by the time you get around to it." 

Unfortunately, when a future generation looks back into our pres- 
ent history and finds this little controversy, there will be but one 
comment, "How very shortsighted." The only serious preservation 
efforts made so far have been those of the Museum of Modern Art 
and of The National Archives. The situation is still far beyond 
solution with the meager budgets of these organizations and with 
their limited powers, as they do not ordinarily become actively con- 
cerned with the preservation of material until long after the material 
is first released for use. (In the interim, the original is often altered, 
mutilated, destroyed, or partially damaged by the unrecorded re- 
moval of scenes or sequences.) Attempted preservation at this late 
stage is quite like trying to close the stable door after the horse is 
stolen. 

If some of today's expansive dreams are to come true, preservation 
(and its corollary, storage) must be planned, and the time is now. 
We must design our film-handling methods to make the long-term use 
of an educational film possible. This must be thought out before a 
film is produced, not after the originals are irretrievably ruined. This 



420 W. H. OFFENHAUSER, JR. Vol 43, No. 6 

cannot be accomplished by our present haphazard and planless 
approach; for example, a Kodachrome original of long-term useful- 
ness (as judged by the subject matter) that is handled in the present 
planless way will not last even 6 months. Such a film will be torn to 
shreds long before it has outlived its usefulness. Today the owner of 
a priceless 16-mm original ships it out of his sight for the making of 
prints to a laboratory or other nominal caretaker where others are 
authorized to make almost limitless copies of it without any handling 
precautions and ruin it in the process. Once ruined, the owner 
frantically hunts for a copy that is in good condition, hoping to use 
this as a printing master from which to make the additional copies 
he needs. This story does not have a happy ending; it is rare that 
such an unmarred copy can be found. And so it ends a valuable 
original leaves nothing behind for future study except some useless 
scrap. 

Under today's wartime conditions, the prospect of a 6 months' 
probable life for a Kodachrome original is quite discouraging, espe- 
cially if the subject matter is vital (such as a subject on malaria, for 
example) and should have a long planned life. Assuming basic 
treatment, this might run to 20 years or more. 

It is true that during peacetime the pace is not so fast and the 
probable life of the hypothetical malaria subject might run to 2 or 3 
years; but even this is disappointing if we are thinking in terms of a 
20-year useful life. While the calendar life of a Kodachrome original 
may be considerably longer during peacetime than during war, this 
results far more from the fact that the total number of prints of the 
subject is smaller than because the handling of the material is better 
coordinated and planned. The industrial and educational uses for 
films demand a far longer calendar life. This can be obtained if it is 
planned beforehand. It is perfectly feasible with today's materials 
and methods if the plan is rigidly followed. 

The Three Stages of Storage. Webster defines preservation as 
"the act or process of preserving or keeping from injury or decay." 
For an original 16-mm film, therefore, the objective, is to keep and save 
the originals from injury or decay (which can be accomplished by 
storing the originals under suitable physical conditions) and at the 
same time provide copies for use that are derived from those originals. 
As it is impossible to "have one's cake and eat it too," it follows that 
the release prints shall be made from intermediate copies during the 
time the originals are in proper storage. 



Dec., 1944 PRESERVING ORIGINALS OF EDUCATIONAL FlLMS 421 

The general method is not new; a modification of it has been used 
for years by the entertainment motion picture industry. Briefly, 
there are 3 stages of storage : 

Stage 1. The originals (in the custody of the owner) are in "dead" storage 
under suitable conditions. (Temperature constant and maintained in the range 
40 to 50 F.) 

Stage 2. The intermediate copies (in the custody of the laboratory or other 
processor) are in "live" storage under the best conditions possible yet assuring 
ready availability for the making of copies. The intermediate copies are used to 
provide release prints. 

Stage 3. The release prints available for ready use yet stored under the best 
available conditions. (Temperatures above room temperature to be avoided 
where possible, and sudden changes in temperature to be avoided where possible.) 

The responsibility for storage falls upon the parties logically re- 
sponsible the owners for the originals, the processors for the inter- 
mediate copies, and the libraries or other users for the prints. This 
arrangement has all the advantages of the customary handling of 
"protection copies," with the further advantage that possible damage 
or loss is anticipated. 

The Mechanics of the Method. The mechanics of the method 
are simple. Once each year the originals are withdrawn from stor- 
age. The user of the subject advises the laboratory or processor of 
the probable requirements for release prints for the forthcoming 
year. The laboratory is then asked to make up all intermediate 
copies (derived directly from the originals) necessary for a full 
year's operation. These are all made up at one time. 

As soon as the intermediate copies specified above are completed, 
the originals are returned to the owner for stage 1 storage for the 
forthcoming year. This storage presumes the best conditions 
known; such conditions are not assured merely by the appearance of 
a warehouse bill once each month. For 16-mm originals (such as 
Kodachrome picture and 16-mm track negative) storage may be 
quite simple, as described later in this paper. The important charac- 
teristic of. the method is that originals remain in "dead" storage a 
very long time as compared with the length of time they are being 
used for the making of intermediate copies. Storage for 51 weeks of 
the year and use for one week, as indicated, would represent a typical 
schedule. 

It may well happen that the owner of a film will underestimate (or 
overestimate) his need for prints during a particular year. This 
will not vitiate the utility of the suggested preservation method unless 



422 W. H. OFFENHAUSER, JR. Vol 43, No. 6 

he fails to learn by his experience. Time and a little experience will 
provide the best solution concerning operational details. 

With regard to the suggested interval of one year, there is nothing 
sacred about it. It is the author's opinion that with present mate- 
rials handled in the present manner, this interval represents the best 
compromise starting point for the various factors involved. 

Print Quality. It should be obvious that good quality is as- 
sumed in all prints manufactured in accordance with this method, 
not merely good prints in the sample lot. * With the original suitably 
preserved, it should be an easy matter to check quality of release 
prints made by one laboratory with release prints made by another or, 
for that matter, to check the quality obtained at one time with the 
quality obtained at another. 

Up to this point, only Kodachrome originals have been discussed. 
The case of 16-mm reversal is functionally just the same as the case 
for Kodachrome. The current interest in Kodachrome arises from 
the problems now being faced that are already acute. Without 
radical changes in the present manner of handling, the situation can 
not but become progressively worse. In the case of reversal, the 
situation has not been so obvious since the demand for black-and- 
white prints from 16-mm originals has not grown at the same tre- 
mendous rate as the demand fof color prints. Should the demand for 
black-and-white prints grow at the same rate, however, the interest 
will be just as keen and the problems no less serious. 

2500 Copies from a Single Original. A question often asked is 
"What is the largest number of Kodachrome duplicates possible 
from a Kodachrome original assuming that the originals are 

* The difference in quality between sample prints supplied by the producing 
contractor and subsequent lots is now aggravated by an unfortunate circum- 
stance in government contracts for training films and the like. The producing 
contractor is called upon to deliver the picture original, the sound negative origi- 
nal, one duplicate negative of the picture, one duplicate negative of the sound, and 
3 composite black-and-white prints. The composite prints and the intermediate 
films have no relation whatever to the production processes used in the labora- 
tories that contract to manufacture the release prints. There is no guarantee 
that the materials, equipment, processes, and methods used in release printing 
will be capable of reproducing the quality of the sample prints; nor is there any 
clause in the release printing contract by which prints inferior to the sample are 
rejected. The result of this contract method may be good "sample" prints, but 
because of the absence of quality specifications and suitably planned release print 
procurement, release print quality is questionable, and there is no assurance that 
the life of an original will not be cut short by improper handling. 



Dec., 1944 PRESERVING ORIGINALS OF EDUCATIONAL FlLMS 423 

properly stored and handled?"* If printing intermediate copies are 
made for release printing, at least 50 such intermediates can be made 
from a Kodachrome original properly prepared and carefully handled. 
If each of these intermediate copies is used to make release prints, at 
least 50 release prints can be made from each intermediate copy. If 
each intermediate copy is printed as a one-light master (as it should 
be in most cases), the number of release prints from an intermediate 
master copy may be increased to 100 or 150; on some films already 
printed the number has run over 250. A good place to start, how- 
ever, will be 50 prints from each intermediate copy, and it would be 
well to consider the difference between 50 prints and any larger num- 
ber as quality insurance necessary to maintain the smallest quality 
differential between the first production print and the fiftieth. 

Storage Recommendations. For proper storage, it is advisable 
to follow closely the recommendations of the film manufacturers. 
For Kodachrome, it is first necessary to clean the film lightly yet 
thoroughly; carbon tetrachloride (Carbona) sparingly applied is 
probably the best cleaning agent. The film should be wound firmly 
on a core without cinching and placed in an ordinary metal film can. 
Cleaning and packing is best performed in a dust-free air-conditioned 
room where the temperature is near 65 or 70 F and the relative humid- 
ity around 40 per cent. 

The film cans are then identified and sealed Kodatape is excellent 
for the purpose. (Certain film cans made by Bell and Ho well and 
others have holes in the underside of the can that must be sealed to 
accomplish the purpose. Kodatape may be used for this sealing 
also.) After such sealing, merely put the cans lying flat in an 
electric refrigerator set to maintain a constant temperature in the 
range 40 to 50 F. 1 (The storage space actually used and the accuracy 

* For maximum print-to-print uniformity and quality of release prints, an 
intermediate color duplicate of the picture should contain all the color and timing 
correction necessary to permit release printing at one light under a single set of 
predetermined conditions (such as color temperature of the source and filter color- 
balance) . A good starting point is the current picture color duplicating recom- 
mendations of the Eastman Kodak Company. Once proper timing and color 
correction has been obtained in a test intermediate duplicate, all intermediate 
duplicates required for the forthcoming year should be exposed and color de- 
veloped as a single lot. Side-by-side projection of each such intermediate dupli- 
cate with the test intermediate duplicate will quickly indicate to an alert and in- 
formed inspector which copies show deviations in quality beyond the normally 
small process variations that are to be expected. 



424 W. H. OFFENHAUSER, JR. Vol 43, No. 6 

of temperature control employed is a matter of compromise among 
the various factors involved.) 

For the black-and-white sound track negative, it is desirable that 
it be made upon film base of low shrinkage (such as Eastman Kodak 
5372}. The only other physical requirement that needs mentioning 
at this time is that the film be properly washed and dried. Under 
present conditions, most production laboratories developing 16-mm 
sound negative as a regular part of their business do not have much 
difficulty with excessive hypo content, but their products are not, 
for the most part, properly dried. For this reason, when 16-mm 
sound track negative is to be stored, the film should be loosely wound 
and permitted to become moisture-stabilized by drying at room 
temperature and humidity for 24 to 48 hr. (Room temperature is 
presumed to be 65 F; humidity to be 40 per cent relative.) From 
that point on, the storage and preservation procedure is the same as 
for Kodachrome. 

It may well be asked, "Are such simple storage techniques ade- 
quate?" The best answer to this question is that for acetate base 
films (such as the Kodachrome picture and the sound track negative 
discussed), the effectiveness of further measures that have been con- 
sidered has been doubtful and, at the same time, costly. Until such 
time as the more complicated procedures justify their costs, they 
should be looked upon with suspicion for use with ordinary films. 

DISCUSSION 

MR. BRADLEY: I am speaking as Chairman of the SMPE Committee on Pres- 
ervation of Film. As the membership knows, this Committee has given con- 
siderable thought to the problem of preservation, and we are glad to have Mr. 
Offenhauser give this additional emphasis to the problem. In a manner of speak- 
ing he has sounded an alarm which is timely; that is, the danger of losing certain 
motion picture records of the present war effort. 

Let me hasten to add, however, that constructive work is being done in an 
effort to preserve current and pertinent motion picture films relating to the prose- 
cution of the present military conflict. In the first place, The National Archives 
is continuing its activities in terms of government motion pictures of an archival 
or record character. In the second place, The Library of Congress is collecting 
and preserving certain categories of motion picture film principally as library 
material. Again, the United Nations Central Training Film Committee is taking 
steps to preserve its collection of training film. In all cases efforts are being made 
to preserve not only a negative and master positive of each film subject, but a 
reference projection print as well. 

In the case of color film, the members of the Committee on Preservation of Film 
would welcome any contribution that can be made which would promote the 



Dec., 1944 PRESERVING ORIGINALS OF EDUCATIONAL FlLMS 425 

longevity of this type of film. As far as the Chairman knows, the dyes used in the 
making of color film are fugitive and unstable in character. In view of this situa- 
tion governmental agencies are being urged to make a black-and-white copy of 
each color film as an extra insurance precaution. 

REFERENCE 

1 CALHOUN, J. M.: "The Physical Properties and Dimensional Behavior of 
Motion Picture Film," /. Soc. Mot. Pict. Eng., 43, 4 (Oct., 1944), p. 257. 



CALCIUM SCUMS AND SLUDGES IN PHOTOGRAPHY 5 

R. W. HENN AND J. I. CRABTREE** 



Summary. Calcium salts may be introduced into photographic processing solu- 
tions from (a) the water supply, (b) the emulsion, or both, and these salts combine with 
some of the developer constituents to form insoluble compounds which may appear 
as (1) a sludge suspended in the developer or accumulated on the filters, (2} a scum on 
the film, or (3) a scale on rollers, sprockets, racks, and the walls of tanks. The control 
of the water supply will reduce the quantity of these precipitates and the scum may 
be removed by suitable acid rinse or acid fixing baths, but calcium-sequestering agents 
are often used for mope complete control. When selecting these agents, their calcium- 
sequestering power, stability, photographic effect, and their effect when carried over 
into the fixing bath must be considered, and on the basis of these requirements, sodium 
tetraphosphate was found the most suitable, f 

Appropriate quantities of sodium tetraphosphate added to the developer were found 
to (1} prevent sludge formation in mixing, storing, or use of the developer, (2) prevent 
the formation of scum on the film when in the developer, and (3) greatly diminish the 
rate at which incrustations accumulate on the tank walls, sprockets, and mechanical 
parts. 

If developers are stored at high temperatures, the poly phosphates present tend to 
hydrolyze to the simple phosphates which, when carried over into the fixing bath, may 
precipitate as aluminum phosphate. This hydrolysis does not occur on storage of 
the dry solids and only very slowly below 85 F when in solution. Solutions stored 
at high temperatures or for prolonged periods may be protected by the addition of sodium 
citrate which extends the life of the tetraphosphate solution and prevents precipitation 
in the fixing bath if hydrolysis has occurred. 

(A) INTRODUCTION CALCIUM PRECIPITATES 

Calcium and magnesium salts are usually the chief impurities 
present in water supplies, and they often cause difficulties in photo- 
graphic processing, namely, (1) turbidity and sludging of the de- 
veloper, (2) scum on the surface of film and prints, and (3) scale 
deposits on hangers, rollers, sprockets, racks, and the walls of tanks. 
Precipitation most frequently occurs in the developer but may also 
take place in fixing baths, toning solutions, etc. In the case of de- 

* Presented Oct. 17, 1944, at the Technical Conference in New York. 
** Kodak Research Laboratories, Rochester, N. Y. ; Communication No. 968. 

t Patent applied for. 
426 



CALCIUM SCUMS AND SLUDGES 427 

velopers, the precipitate consists of calcium sulfite, or a form of basic 
calcium sulfite, mixed with calcium carbonate and possibly magne- 
sium carbonate, depending on the constitution of the developer and 
the quantities of impurities present. The tendency to precipitate 
and the character of the precipitate formed also differ with the 
developer (see Table 1). In general, (a) low pH developers with a 
high concentration of sulfite, such as D-76 or D-103, and (b) those 
with a relatively high concentration of carbonate, such as D-72 and 
D-16, show the most marked tendency to cause precipitation. 

Properties of Calcium and Magnesium Precipitates. Calcium 
sulfite is a white compound which crystallizes in the hydrated form 
(CaSO 3 -2H2O). Only about 43 parts per million are soluble in water 

TABLE i 
Calcium Concentrations to Give Precipitate in Developers 



Calcium Chloride 
Immediate Precipitate At Equilibrium 



(Grams per 
Liter) 


P.P.M. 


(Grams per 
Liter) 


P.P.M. 


/>H 
Value 


0.3 


300 


0.07 


70 


8.2 


0.35 


350 


0.10 


100 


8.7 


0.5 


500 


0.25 


250 


9.6 


0.35 


350 


0.12 


120 


10.3 


0.7 


700 


0.15 


150 


10.4 


1.7 


1700 








13.0 


0.3 


300 


0.10 


100 


10.0 



Developer 

Kodak DK-20 
Kodak D-76 
Kodak DK-60a 
Kodak D-72 (1:2) 
Kodak D-19 
Kodak D-8 
Kodak D-16 



at 18 C (about 65 F), and like many calcium compounds, it is some- 
what less soluble in hot water. There is evidence for the existence 
of basic sulfites (Ca x (OH) y (SO 3 ) z ) when precipitation occurs from 
alkaline solutions. Calcium carbonate (CaCOs) is also a white 
compound and is even less soluble in water than the sulfite, namely, 
12 to 14 parts per million. Magnesium sulfite (MgSO 3 -6H 2 O) is 
relatively more soluble (1250 parts per million) and would not 
ordinarily precipitate in a developer, but magnesium carbonate 
may precipitate, although its solubility varies greatly with the condi- 
tions of formation. All of these compounds are soluble in dilute 
acids, such as a 1 per cent acetic acid solution. 

Types of Precipitates. (1) Developer Sludge. The white pre- 
cipitate which often forms in developers freshly mixed with hard 
water has been shown by Crab tree 1 to consist principally of calcium 
sulfite, while in developers of high carbonate content the sludge has 



428 



R. W. HENN AND J. I. CRABTREE 



Vol 43, No. 6 



been found to be mostly calcium carbonate. In low pH developers, 
such as D-76, the deposit is largely crystalline but, in the more 
alkaline developers, it tends to be flocculent. In general, this sludge 
is more of an annoyance than a real difficulty unless it is necessary 
to observe the progress of development. It will rarely remove suffi- 
cient sulfite or carbonate to change the photographic properties 
of the developer. The sludge becomes serious when developing 




FIG. 1. Calcium Sulfite Scum. This white deposit of calcium sulfite was pro- 
duced on a film processed in the D-76 developer and fixed in plain hypo. 

paper prints under a safelight since enough sludge is often formed 
to interfere with clear visibility. 

(2) Scum. Probably the most objectionable type of calcium de- 
posit is a white scum on the surface of the film (see Fig. 1). This 
scum tends to cling strongly to those areas which may have been 
touched with the hands during development and takes the form of 
well-defined finger marks, but it is sometimes quite evenly distributed 
over the surface of the film. It is slowly soluble in fresh acid fixing 
bath and the rate of solution is greatly aided by agitation. However, 



Dec., 1944 CALCIUM SCUMS AND SLUDGES 429 

it may dissolve more slowly than the silver halide, especially if the 
bath has been used sufficiently to lower the acidity, in which case 
the film may appear to fix very slowly. Since the scum may be 
wiped off the surface with the fingers, this test may be used to dis- 
tinguish it from the unfixed silver halide. It also dissolves slowly 
in the wash water and may be wiped off before drying although, in 
some forms, it is so transparent that it is not readily visible until dry. 

(3) Scale. The third objectionable type of calcium precipitate 
is a scale on the walls of the processing tanks and on film rollers, 
sprockets, racks, and other equipment. When the rate of deposi- 
tion is slow, a tough deposit is formed which is very difficult to remove. 
It is particularly troublesome in the case of continuously used solu- 
tions as in deep tank work where it incrusts upon tank walls, hangers, 
sprockets, and nozzles. Analysis of a tank scale deposited from theD-76 
developer disclosed that it consisted almost entirely of calcium salts, 
about 75 per cent as the sulfite and 25 per cent as the borate. 

(4) Drying Spots. When films are washed in hard water and 
are imperfectly squeegeed before drying, white deposits are apt to 
remain on the surface of the film after evaporation of the water. 
These deposits may be prevented by (a) a final rinse in distilled 
water, (b) the use of a wetting agent which permits the water to 
drain evenly from the film, or (c) thorough wiping or squeegeeing of 
the film before drying. 

(B) SOURCES OF CALCIUM IN THE DEVELOPER 

Calcium and the slightly less troublesome magnesium salts are 
found to some extent in all natural waters except fresh rain water, 
and may be present as carbonates, bicarbonates, chlorides, or sul- 
fates. 

Table 2 reproduces values taken from the U. S. Government 
Bulletin on "The Industrial Utility of Public Water Supplies in the 
United States" (1932), and indicates that the "hardness" of water 
supplies varies greatly; in general, for surface supplies possibly 100 
to 200 parts of "hardness" (calculated as calcium carbonate) per 
million is fairly typical. Most well water is much harder, and 
250 to 600 parts per million is not uncommon. In Hollywood, the 
average hardness value for several laboratories was 144 parts per 
million, while the hardness of a Culver City well supply was 305 
parts per million. In general, this hardness will be divided between 



430 R. W. HENN AND J. I. CRABTREE Vol 43, No. 6 

calcium and magnesium in a 2 : 1 or 3 : 1 ratio, with calcium as the 
chief impurity. 

A second source of calcium is from the gelatin of the photographic 
emulsion. Gelatin is produced by "liming" hides, that is, by treat- 
ing them with calcium hydroxide. The proportion of calcium salts 
present may be as high as 1 per cent of the weight of the gelatin. It 
has been calculated that during a long exhaustion life as much as 
1 gram (15 grains) of calcium salts could accumulate in a liter (32 

TABLE 2 

Hardness of Typical Water Supplies* 

Total Hardness 
(As Parts Calcium 

Carbonate per 
City Source Million) 

Portland, Ore. Bull Run River 9 

Boston, Mass. Wachusett Reservoir 15 

New York, N. Y. Catskill Supply 20 

Rochester, N. Y. Lake Ontario 105 

Cleveland, Ohio Lake Erie 120 

Denver, Colo. Platte River Tributaries 121 

Chicago, 111. Lake Michigan 125 

Hollywood, Calif. Average of 5 Motion Picture 

Laboratories 144 

Minneapolis, Minn. Mississippi River 172 

San Antonio, Texas Wells 220 

Jacksonville, Fla. Wells 270 

Culver City, Calif. Well 305 

Wichita, Kansas Wells 411 

Chikasha, Okla. Washita River 626 

* Values from "The Industrial Utility of Public Water Supplies in the United 
States" (1932), U. S. Department of the Interior, Geological Survey Water Supply 
Paper No. 658. 

oz) of developer which would be equivalent to a concentration of 
1000 parts per million. 

These 2 sources of calcium, (1) the water, and (2) the emulsion, 
must be considered when studying the control of difficulties attrib- 
uted to calcium salts. 

(C) CALCIUM-SEQUESTERING AGENTS 

The prevention of calcium precipitates (including scum and scale 
as well as sludges) is far preferable to their removal, which may be 
difficult and time-consuming. They may be prevented to some 
extent by treating the water supply with water softeners, but the 



Dec., 1944 CALCIUM SCUMS AND SLUDGES 431 

calcium from the gelatin will accumulate as exhaustion progresses 
and still cause difficulty. Suitable methods of treating the water 
include (1) boiling to remove temporary hardness, (2) removal by 
Zeolites and synthetic resins, and (3) precipitation of the calcium as 
oxalate and filtering. 2 

However, the use of calcium-sequestering agents will not only con- 
trol the calcium present in the water but also that coming from the 
film during processing. These agents segregate or "sequester" the 
calcium in the form of a complex compound which, although soluble, 
no longer yields the reactive calcium ions which combine with the 
sulfite (or carbonate) to form the troublesome precipitates. 

(1) Organic Acids. One group of sequestering agents consists 
of organic hydroxy acids or their salts, such as tartaric acid, sodium 
citrate, etc. They are effective, at least temporarily, when em- 
ployed in sufficiently high concentrations, such as 50 to 100 grams 
per liter, but when carried over into the fixing bath cause loss of 
hardening power by combining with the alum. Certain a-amino 
polycarboxylic acids have also been employed 3 but are relatively 
expensive. 

(2) Polyphosphates. A second type of sequestering agent is of 
greater practical importance. 4 ' 5 This comprises a group of complex 
phosphates to which the term "polyphosphate" has been applied. 
The most common of these are (1) the sodium salt of polymerized 
metaphosphoric acid, known as sodium metaphosphate or under 
the trade name "Calgon," (NaPOs^, and (2) the sodium or potassium 
salts of pyrophosphoric acid, NaJ^O? and K4P2O7. Calgon has 
been widely used experimentally during the past few years and for 
large-scale work by at least one motion picture laboratory. Another 
member of this group which has not previously appeared in the 
photographic literature but which is especially effective is (3) sodium 
tetraphosphate, NaePiOis. Some of the comparative properties of 
these phosphates are given in Table 3. 

A sequestering agent placed in the developer should not affect its 
photographic properties, should remain unchanged over considerable 
periods, and should not react adversely with the fixing bath or 
other solutions into which it may be carried. Consequently, tests 
made with these polyphosphates included (1) the calcium-sequester- 
ing properties, (2) keeping properties, (3) effect on developer activity, 
fresh and aging, and (4) tendency to precipitate with the fixing 
bath, fresh or on aging. 



432 



R. W. HENN AND J. I. CRABTREE Vol 43, No. 6 



(a) Calcium-Sequestering Properties. The values (see Table 3 and 
Fig. 2) were determined by adding a dilute calcium chloride solution 
to the developers containing various concentrations of the poly- 
phosphates until a light precipitate was visible. Since this pre- 
cipitate tends to form slowly, long standing periods (24 hr) were re- 



TEMPERATURE , F 



4 MONTHS 
2 MONTHS 
4 WEEKS 
2WEEKS 



80 


10 


) 12 


3 M 


K3 1C 


O li 


10 


200 


0,000 

8,000 


A- 


-^ 














4,000 


\ 


\ 
















- 


\ \ 














ooo 
boo 




A 


\e. 












600 g 






"o\ 












4OO D 






\* s 


is 












" 




J 


i 










6 

z 

100 fc 








s&\ 


"x 








so 

60 ^ 








~Y&' 


V 








40 U 








\ 


\ 
















N 


\ 








U 
20 2 










\ 


\ 






P 

IO 
8 












\ 


\ 




4 














. 


\ 
















\ 




1.0 
08 


















0.6 



20 30 



80 90 



40 50 60 70 
TEMPERATURE, C. 

EFFECT OF TEMPERATURE ON RATE OF 
HYDROLYSIS OF SODIUM TETRAPHOSPHATE 

KODAK DK-6OA DEVELOPER (pH=96) 

FIG. 2. Illustrating the effect of temperature 
on the keeping properties of sodium tetraphosphate 
in the developer solution. Hydrolysis occurs 
rapidly at high temperatures but decreases rapidly 
as the temperature drops and becomes negligible 
under normal conditions. 



quired, or the reaction was accelerated by rotating the reaction tubes 
in warm water; in this case, virtual equilibrium was attained in 30 
min. In much of the preliminary work, the value to produce an im- 
mediate precipitate was used and this figure has been found to be 
roughly proportional to the final equilibrium value. In general, it 
has been found necessary to employ a much higher concentration of 
pyrophosphate than of either tetraphosphate or of metaphosphate 
to produce a given calcium-sequestering action, while the magnesium- 



Dec., 1944 CALCIUM SCUMS AND SLUDGES 433 

sequestering powers of the pyrophosphate and tetraphosphate appear 
to be superior to those of the metaphosphate. The calcium precipita- 
tion tests have been found to run closely parallel to practical exhaus- 
tion or scumming tests. 

(b) Keeping Properties. On prolonged standing when warm or in 
the presence of strong alkali (or acid), the polyphosphates tend to 
hydrolyze to the simple phosphates (orthophosphates). The 
scheme of these hydrolysis reactions for the 3 groups of polyphos- 
phates is represented by the following equations : 

(NaPO,) 6 + 6 H 2 * 6 NaH 2 PO 4 (1) 

Sodium metaphosphate Sodium dihydrogen phosphate 

Na 4 P 2 O 7 + H 2 O * 2 Na 2 HPO 4 (2) 

Sodium pyrophosphate Disodium hydrogen phosphate 

Na,P 4 18 + 3 H 2 *2 NaH 2 PO 4 + Na^HPO, (5) 

Sodium tetraphosphate 

This hydrolysis results in (a) loss of calcium-sequestering power, 
and (b) change in pH value. The sodium dihydrogen phosphate is 
acid while the disodium hydrogen phosphate is alkaline; the mixture 
as represented by Eq (3) has a pH of about 6.5, or is nearly neutral 
and consequently produces little change in activity, (c) The release 
of phosphate ions in the developer which, when carried over into the 
fixing bath, react with the alum to form insoluble aluminum phos- 
phate which deposits as a sludge in the fixing bath and as a white 
scum on the film, which is more difficult to remove than calcium 
sulfite. The hydrolysis of the polyphosphates occurs only in the 
presence of moisture. The solids will keep indefinitely in well- 
stoppered bottles, but slowly deteriorate in the presence of moist 
air. 

Normal hydrolysis is a very slow process, requiring weeks or 
months at normal temperatures, and it was necessary to warm the 
solutions in order to study relative rates. The values in Table 3 
were determined by heating solutions containing the polyphosphate 
and a calcium salt and taking the time of precipitation as a measure of 
the decomposition of the polyphosphate-calcium complex. These 
tests, plus prolonged keeping tests at lower temperatures, showed 
that the tetraphosphate possessed a definite advantage with regard 
to stability. 

(c) Chemical Effect. The polyphosphates are not active photo- 
graphically, but may influence the pH (alkalinity) of the less active 
developers if used in considerable concentrations. Sodium meta- 



434 



R. W. HENN AND J. I. CRABTREE 



Vol 43, No. 6 



phosphate is ordinarily somewhat acid, and the pyrophosphates are 
quite alkaline, while the H of sodium tetraphosphate differs but 
little from that of low-activity negative developers, such as D-76, and 
therefore has little effect upon the rate of development. 

(d) Tendency to Precipitate in the Fixing Bath. The phosphates 
form insoluble compounds with aluminum, a constituent of most acid 
fixing baths. A precipitate will form in an alum solution to which 
solutions of the polyphosphates are added. Practically, in a well- 
designed fixing bath, such as Kodak F-5, only the pyrophosphate is 
likely to cause trouble. 

TABLE 3 

Comparison of Polyphosphates 



(3) Sequestering 

Power 
Grams per Liter 



(1) Name 



(2) Formula 



In 
D-76 



In 
D-72 

(1:2) 



(5) Alum 
Precipitation 

(4) Keeping Properties Alum Phosphate 

(212 F) to Cause to Cause 

Precipi- Precipitate 

In D-76 In D-72 tate in F-5 



Sodium meta- 

phosphate (NaPOs^ 2.0 0.6 4 min 4 min 7 gm over 5 gm 

Sodium pyro- 
phosphate Na 4 P2O 7 1.5 0.4 l x /2 min 2 min 3 gm 2 gm 

Sodium tetra- 
phosphate Na 6 P 4 Oi3 2.0 0.75 6 min 7 min 10 gm over 5 gm 

Notes : 

Column 3 Sequestering Power: In terms of grams of calcium chloride per liter 
to cause a light precipitate. (1.0 Gram per liter = 1000 parts per million.) 

Column 4 Keeping Properties: Reported as minutes for calcium to precipitate 
from solutions held at 100 C (212 F). 

Column 5 Alum Precipitation: (a) Grams of potassium alum to precipitate 
1 per cent polyphosphate solution. (&) Grams of phosphate to cause precipitate 
in Kodak F-5 fixing bath. 

The simple phosphates formed on hydrolysis of the polyphosphates 
are a greater source of difficulty, and 50 per cent hydrolysis of as low 
a concentration as 0.5 gram of one of the polyphosphates in a liter 
of developer can produce an aluminum phosphate scum under cer- 
tain conditions. The degree of stability of the polyphosphate is 
therefore very important. 

From the above discussion and from Table 3 it is seen that sodium 
tetraphosphate is probably the most suitable of the group of poly- 
phosphates. It has slight advantages over the metaphosphate in 
sequestering power, stability, and alum precipitation propensity and 



Dec., 1944 



CALCIUM SCUMS AND SLUDGES 



435 



causes the least change in alkalinity when fresh or hydrolyzed. 
Sodium pyrophosphate (also potassium pyrophosphate) is less de- 
sirable. 

(D) SODIUM TETRAPHOSPHATE AS A SEQUESTERING AGENT 

(1) Effect of Concentration. The behavior of the various se- 
questering agents is strongly dependent on the pH and constitution 




O2 4 6 8 IO 12 14 16 18 2O 
SODIUM TETRAPHOSPHATE, G-RAMS/ LITER 

EFFECT OF TETRAPHOSPHATE CONCENTRATION 
ON CALCIUM SEQUESTERING- POWER 

FIG. 3. The behavior of sodium tetraphosphate as a 
sequestering agent is very dependent on the nature of 
the developing solution. The existence of an optimum 
concentration is found with other low pH developers as 
well as D-76 while high />H developers show a progres- 
sive effect only and require higher concentrations of the 
tetraphosphate . 

of the developer. The effect of increasing concentrations of sodium 
tetraphosphate in 3 developers is shown in Fig. 3. The sequestering 
action is seen to be more powerful in the low pH developer (D-76) than 
in the relatively high pH developers (D-19 and D-16). Also, in 
the case of the D-76, a maximum effect is obtained at low tetra- 
phosphate concentrations; a similar effect is obtained with other 
low pH developers and with metaphosphate, as well as tetraphos- 



436 



R. W. HENN AND J. I. CRABTREE Vol 43, No. 6 



phate. The cause of this maximum has not been determined 
definitely although it has been studied in several groups of experi- 
ments. The crystalline precipitate formed at low tetraphosphate 
concentrations is apparently calcium sulfite, while at high phosphate 
concentrations the flocculent precipitate formed appears to be a 
complex phosphate. 

It is desirable to employ as low a tetraphosphate concentration 
as possible to reduce the dangers resulting from possible hydrolysis 
on prolonged or high temperature storage. In the low and medium 
pH developers, such as Kodak D-103, DK-20, D-76, DK-50, or DK- 
60a, 0.5 gram of sodium tetraphosphate per liter provides adequate 

TABLE 4 

Recommended Tetraphosphate Concentrations 

Grams per Calcium- 

Liter Sequestering Estimated Life 

(Diluted Developer) 25 Per Cent Hydrolysis at: 

Di- P.P.M. Calcium 



Developers Stock luted Chloride 

Group ILow Activity 
Kodak DK-20, D-23, 
D-25.D-76, D-103 

Group 2 Medium Activity 
Kodak DK-50, DK-60a, 
DK-93 

Group 3 Carbonate Developers 

Kodak D-11,D-16,D-19 2.0 2.0 About 500 
Kodak D-52 4.0 2.0 About 500 

Kodak D-72 6.0 2.0 About 500 



70 F 



90 F 110 F 



0.5 0.5 Over 1000 3 yrs 9 mos 6 wks 



0.5 0.5 About 800 2 l / 2 yrs 6 mos 4 wks 



I 1 /* 



3 mos 
3 mos 
3 mos 



2 wks 
2 wks 
2 wks 



protection against calcium entering from the water or from the 
film. In the carbonate developers, such as D-16, D-19, or D-72, about 
2 grams of tetraphosphate per liter of developer as diluted for use 
will protect against all but the hardest water combined with moder- 
ate exhaustion. While higher concentrations may be employed for 
very hard water, such developers should not be stored for long 
periods since hydrolysis of a relatively small proportion of the 
phosphate might cause difficulties. Table 4 lists the recommended 
concentrations for most of the Kodak developers. 

(2) Effect on Calcium Precipitates. Developers containing 
the tetraphosphate concentrations mentioned above display very 
satisfactory freedom from propensity to give precipitates, namely : 

(1) Their sludging propensity is greatly reduced, either during 
mixing or when diluted with hard water or during exhaustion. 



Dec., 1944 CALCIUM SCUMS AND SLUDGES 437 

Some sludge may be anticipated on severe exhaustion and prolonged 
standing owing to (a) the slow release of some calcium ions, (b) the 
formation of free silver, especially in the D-76 type of developer, 6 
and (c) the presence of foreign substances entering from the emul- 
sion. In the case of a print developer such as Kodak D-72 diluted 
with hard water followed by rapid (one day) exhaustion, the im- 
provement in clarity and print visibility is usually very great. 

(2) No calcium scum has been encountered even with developers 
otherwise displaying the greatest scumming tendency, either fresh 
or on prolonged exhaustion, when the tetraphosphate was added to 
both the developer and the replenisher. 

(3) Almost complete freedom from tank scale and incrustation of 
equipment has been found for both negative and positive developers 
during extended use of polyphosphates in the Kodak processing 
laboratories. 

(3) Keeping Properties. Difficulty with hydrolysis of the tetra- 
phosphate has been noted under simulated tropical conditions, but 
this reaction is very dependent on temperature. Fig. 2 shows the 
effect of temperature on the rate of hydrolysis of sodium tetraphos- 
phate in DK-60a, a moderately alkaline developer (pH = 9.6). 
Data for D-16 would be approximately' similar. Samples of the de- 
veloper containing the tetraphosphate were held at various tempera- 
tures for a series of times and the degree to which hydrolysis had 
occurred was then determined by two tests: (a) the tetraphosphate 
remaining was indicated by the calcium-sequestering powers of the 
developer, and (b) the orthophosphate formed was measured by pre- 
cipitating it as the ferrous salt from a weakly acid solution. The 
values obtained with the stored developers were compared with those 
determined using known mixtures of tetraphosphate and orthophos- 
phate corresponding to different degrees of hydrolysis in the de- 
veloper. The extreme dependence of hydrolysis on temperature is 
clearly shown in the figure. It was necessary to use a logarithmic 
plot in order to reproduce the wide variances in time for relatively 
slight changes in temperature. Checks run for 3 months at room 
temperature indicated that no pronounced phosphate hydrolysis 
occurred in this typical developer under favorable conditions, while 
keeping tests in the more alkaline developer, D-72, have shown only 
10 per cent hydrolysis in 5 months at 75 F. 

In the presence of high sodium carbonate concentrations, such as 
in the D-19 developer or the D-72 stock solution (but not in the 



438 R. W. HENN AND J. I. CRABTREE Vol 43, No. 6 

diluted D-72 developer), a compact precipitate of sodium calcium" 
carbonate (Pirssonite) slowly forms at the bottom of the containing 
vessel, apparently caused by the slow release of calcium ions from the 
tetraphosphate complex. This precipitate is not ordinarily serious 
since it is small in volume and is not easily dispersed to interfere with 
solution clarity, while it does not adhere to the walls to form tank 
scale or form a scum on films. 

(4) Stabilization. Since the chief danger in the use of poly- 
phosphates is the hydrolysis to simple phosphates and the precipita- 
tion of these in the fixing bath, it is important to stabilize them for 
keeping under tropical or summer conditions and to prevent scum 
formation if hydrolysis should occur. The hydroxy acids, pre- 
viously mentioned, and their salts fulfill both of these requirements, 
and sodium citrate is probably the most powerful of those readily 
available at the present time. Used in even relatively small con- 
centrations (2 to 4 times the weight of the tetraphosphate), it will 
double the life of the phosphate and effectively prevent aluminum 
phosphate scum when the tetraphosphate is partially hydrolyzed. 

Greater and more permanent sequestering action is obtained 
from the citrate-phosphate mixture than from, either the phosphate 
or citrate alone. While the concentration of citrate required will 
not appreciably impair the hardening properties of the fixing bath 
or repress development, it will prevent the formation of the aluminum 
phosphate scum. 

(E) RECOMMENDATIONS 

Prevention of Calcium Precipitates. (1) Control of Water 
Supply. If the water supply contains more than 200 to 300 parts 
per million of total hardness expressed as calcium carbonate, the 
load on the sequestering agent may be excessive. If a substitute 
supply is not available, this water may be softened by a commercial 
Zeolite or "Permutit" system, or by one of the newer synthetic 
resin exchange systems. An alternate method is to precipitate the 
calcium from the water by adding about 1 gram of potassium oxalate 
per liter (60 grains per gal) and, after standing, decanting the clear 
liquid. 

(2) Addition of Sodium Tetraphosphate to the Developer. About 
0.5 gram of sodium tetraphosphate added per liter (30 grains per gal) 
of the Kodak D-103, DK-20, D-76, DK-50, or DK-60a developers 
will effectively prevent calcium scum and scale during normal use. 



Dec., 1944 CALCIUM SCUMS AND SLUDGES 439 

If the solution is replenished, the same quantity should be added to 
the replenisher. With carbonate developers, such as Kodak D-16 
D-19, and D-72, 2.0 grams per liter (120 grains per gal) are advisable. 
The employment of sodium tetraphosphate is not advised in de- 
velopers containing caustic soda, such as Kodak D-8 or D-82, since 
(a) the tendency of calcium to precipitate in these developers is 
relatively slight, and (b) the keeping properties of the tetraphosphate 
in these solutions are rather poor. These values apply to the de- 
veloper as diluted for use; if added to a stock solution, as in the 
case of D-72, the concentration should be increased proportionally 
(see also Table 4). 

(3) Use of Phosphate and Citrate. If the developer solution 
is to be stored for long periods or at temperatures in excess of 85 F, 
the danger from hydrolysis may be reduced by employing a com- 
bination of sodium tetraphosphate and sodium citrate. In the 
case of developers containing only borax or Kodalk, 0.5 gram of 
sodium tetraphosphate with 1.0 gram of sodium citrate per liter 
(30 and 60 grains per gal) is recommended. In the case of the car- 
bonate developers, 2.0 grams of tetraphosphate with 8.0 grams of 
sodium citrate per liter (120 grains and 1 oz per gal) should be em- 
ployed. These mixtures are not advised for caustic developers. 

(4) Use of an Acid Rinse Bath. Use of an acid rinse or "stop" 
bath will not prevent calcium sludge or scale in the developer, but will 
remove scum from the film and, at the same time, extend the life of 
the fixing bath. The film is placed in this bath and preferably 
agitated for one to 2 min following development. 

Stop Bath 
(Kodak SB-5) 

Kodak Acetic Acid, glacial 10 cc 

or 

Kodak Acetic Acid, 28 per cent 32 cc 

Kodak Sodium Sulfate (desiccated) 45 gm 

Water to make 1000 cc 

Caution: Acid stop baths should be used with caution when processing film in 
a carbonate developer at high temperatures, or blistering may result. 

This bath may be replenished after processing each 25 rolls per 
gal by adding one-half of the above quantity of acetic acid. Discard 
the bath after 100 rolls per gal. 

Removal of Precipitates. (1) In Developer. If considered ob- 
jectionable, sludges may be removed by filtration or decantation. 7 



440 R. W. HENN AND J. I. CRABTREE Vol 43, No. 6 

(2} Calcium Scum. The scum may be removed as suggested above 
by means of a fresh acid rinse bath. This method is applicable even 
if the scum has dried on the film before being discovered, although 
swabbing of the film while in the acid bath may be necessary. It 
may also be removed by agitating the film in a fresh acid fixing 
bath, such as Kodak F-5. A system employing 2 successive F-5 
fixing baths is very effective in removing calcium scum in addition 
to insuring permanence and adequate hardening. In this system, 
the first bath, when exhausted, is replaced by the relatively fresh 
second bath with resulting economy of material. Calcium scum may 
usually also be removed by swabbing the surface of the film while 
in the wash water, or by wiping previous to drying. 

If the scum is not removed by the acetic acid rinse bath it indicates 
that it is probably an aluminum sulfite scum formed in the fixing 
bath. This aluminum scum is soluble in 5 per cent acetic acid or 2 
per cent sodium hydroxide, but it may be necessary to swab the film 
gently to remove it completely. It is always good policy to harden 
film thoroughly as, for example, in the Kodak SH-1 before this 
treatment. 

It is therefore possible to differentiate between "calcium scum" 
and "aluminum scum" by treating with 1 per cent sodium hydroxide 
which dissolves only the aluminum sulfite. 

(3) Scale. Calcium scale deposits may be dissolved or loosened 
from tanks and hangers with dilute acids. Acetic acid, in a 2 to 5 
per cent solution, is effective in dissolving calcium carbonate 
deposits and will not attack stainless steel; hydrochloric acid, used 
in about a 2 per cent solution, is much more effective in removing 
calcium sulfite and borate deposits, but will corrode stainless steel. 
The equipment may be scrubbed with the acid solution, protecting 
the hands with rubber gloves and avoiding the vapors as much as 
possible, or the tank may be filled with the acid solution and hangers 
immersed in it for about 24 hr to first dissolve or loosen the deposit. 
Scale deposits do not generally cling very tenaciously to polished 
surfaces, such as the walls of stainless steel tanks, and may ordinarily 
be removed with a putty knife. 

ACKNOWLEDGMENT 

The authors gratefully acknowledge the contributions of their 
colleague, Dr. H. D. Russell, to the early stages of this investigation. 



Dec., 1944 CALCIUM SCUMS AND SLUDGES 441 

REFERENCES 

1 CRABTREE, J. I.: "The Nature of a Developer Sludge," A mer. Phot., 12 (Mar., 
1918), p. 126. 

8 CRABTREE, J. I., and MATTHEWS, G. E.: "Effect of Water vSupply in Process- 
ing Motion Picture Film," /. Soc. Mot. Pict. Eng., XVI, 4 (Apr., 1931), p. 437. 

3 Brit. Pat. 496,252, Nov. 28, 1938. 

4 KEISER, K.: "Precipitation in Developers with Hard Water," Brit. J. Phot., 
84 (Apr. 9, 1937), p. 232. 

6 KBISER, K.: "Precipitation in Developers with Hard Water," Brit. J. Phot., 
84 (Mar. 19, 1937), p. 184. 

6 LOBEL, L.: "On the Formation of Colloidal Silver in Photographic De- 
velopers," Bull. Soc. Franc. Phot., 60 (1920), p. 21. 

7 For discussion and illustration of these methods see CRABTREE, J. I., AND 
MATTHEWS, G. E.: "Photographic Chemicals and Solutions," Amer. Phot. 
Publishing Co. (Boston), 1939, pp. 31-38.' 



SOCIETY ANNOUNCEMENTS 

AMENDMENTS OF BY-LAWS 

SPONSOR REQUIREMENTS 

In canvassing for new members, it has been found that many individuals who 
would be worthy candidates for Associate or Active membership were not ac- 
quainted with the requisite number of sponsors for these grades. Therefore, the 
Board of Governors proposed a change in sponsor requirements stated in By-Law 
I, Section 3 (c) and (d), which was published on page 219 of the JOURNAL of 
September, 1944. The amendment was approved unanimously at a business 
session held on October 16 during the recent Technical Conference. 

Therefore, applicants for Active membership shall now give as sponsors at 
least one member of Active or higher grade in good standing, and applicants for 
Associate membership shall give as sponsors at least one member of the Society 
in good standing, or two persons not members of the Society but who are associ- 
ated with the motion picture or allied industries. 

OTHER AMENDMENTS 

Proposed amendments of By-Laws III, V, and VI, as published in the Septem- 
ber JOURNAL, were also voted on by qualified members present at the business 
session on October 16. All were approved and are now in effect. 

EMPLOYMENT SERVICE 

The General Office has received requests from companies desiring motion pic- 
ture engineers and other technical personnel. In addition, some members 
have recently asked the Society for aid in making new business connections. 

In order to render mutual service to members of the Society in this manner, 
the Editor of the JOURNAL will accept notices from business organizations for 
technical personnel, and from members of the Society desiring technical jobs. 
These will be published in the JOURNAL as soon as possible after receipt those 
received before the 15th of the month will appear in the JOURNAL of the follow- 
ing month. 

Notices should be brief and must give an address for direct reply. The Society 
cannot serve as a forwarding agent for inquiries, and reserves the right both to 
edit or reject any notice submitted for publication. 

It is hoped that the establishment of this service will not only benefit members 
of the Society who may desire new business affiliations in the post-war era, but will 
enable employers to make their needs known to a large group of engineers and 
specialists in the motion picture industry. 
442 



SOCIETY ANNOUNCEMENTS 443 

OFFICERS, GOVERNORS, AND SECTION MANAGERS FOR 1945-46 

As a result of the elections held recently, the following is a list of Officers and 
Governors of the Society for the term beginning January 1, 1945: 

** President: DONALD E. HYNDMAN 

** Past-President: HERBERT GRIFFIN 

** Executive Vice-President: LOREN L. RYDER 

* Engineering Vice- President: J. A. MAURERJ 
** Editorial Vice-President: ARTHUR C. DOVVNES 

* Financial Vice- President: ARTHUR S. DICKINSON 
** Convention Vice-President: WILLIAM C. KUNZMANN 

* Secretary: E. ALLAN WILLIFORD 

* Treasurer: M. R. BOYER 

| Governors from the Atlantic Coast Area: 

* FRANK E. CARLSON * CLYDE R. KEITH 
** J. I. CRABTREE * EARL I. SPONABLE 

** REEVE O. STROCK 
J Governors from the Pacific Coast Area: 

** C. R. DAILY ** PETER MOLE 

* EDWARD M. HONAN * HOLLIS W. MOYSE 

* WALLACE V. WOLFE 

Officers and Managers of the Atlantic Coast Section for the term beginning 
January 1, 1945, are: 

* Chairman: CLYDE R. KEITH 

* Past-Chairman: ALFRED N. GOLDSMITH 

* Secretary-Treasurer: M. W. PALMER 

Managers: * E. A. BERTRAM ** G. T. LORANCE 

* JAMES FRANK, JR. ** W. H. OFFENHAUSER, JR. 

*J. J.HOPKINS **H.E. WHITE 

Officers and Managers of the Pacific Coast Section for the term beginning Janu- 
ary 1, 1945, are: 

* Chairman: HOLLIS W. MOYSE 

* Past- Chairman: CHARLES W. HANDLE Y 

* Secretary-Treasurer: SIDNEY P. SOLOW 

Managers: ** J. W. BOYLE * C. O. SLYFIELD 

** F. L. EICH * J. R. WHITNEY 

** H. W. REMERSCHIED * W. R. WILKINSON 

* Term expires December 31, 1945. 
** Term expires December 31, 1946. 

t Appointed by Board of Governors to fill unexpired term of Engineering Vice- 
President. 

J One additional Governor to be appointed by Board of Governors to fill 
vacancy in each area. 



444 SOCIETY ANNOUNCEMENTS Vol 43, No. 6 

BACK ISSUES OF JOURNAL WANTED 

The stock of many early issues of the Transactions and the JOURNAL is being 
depleted rapidly. The General Office of the Society is unable to supply certain 
back issues urgently required by the Armed Forces, libraries, and others who have 
placed orders for complete files of these publications. Therefore, the Board of 
Governors recently authorized the purchase of such issues of the Transactions 
and JOURNALS needed to replenish our stock, a list of which follows : 

TRANSACTIONS JOURNALS 



No. Date Vol No. Date 

1 July, 1916 20 6 June, 1933 

2 Oct., 1916 22 1 Jan., 1934 

5 Oct., 1917 22 2 Feb., 1934 

6 Apr., 1918 22 3 Mar., 1934 

7 Nov., 1918 22 4 Apr., 1934 

8 Apr., 1919 26 5 May, 1936 

9 Oct., 1919 30 1 Jan., 1938 
20 Sept., 1924 30 3 Mar., 1938 
31 Sept., 1927 30 5 May, 1938 

32 4 Apr., 1939 

34 6 June, 1940 



The Society will purchase a quantity of these issues at rates up to 50^ each, 
plus postage, depending on the condition of the copy. Please communicate 
with the General Office, Hotel Pennsylvania, New York 1, N. Y., if you desire to 
dispose of any of the above issues in your possession. 



PACIFIC COAST SECTION 

Local presentation of 3 papers of timely interest, which were delivered before 
the recent 56th Technical Conference in New York, was arranged for the Pacific 
Coast Section meeting on November 1. They were "Application of Sound Re- 
cording Techniques to Airplane Vibration Analysis," by J. C. Davidson and J. G. 
Frayne, "An Airplane Vibration Recorder," by J. C. Davidson and G. R. Crane, 
and "An Airplane Vibration Reproducer," by G. R. Crane, all of Electrical 
Research Products Division of Western Electric Company, Hollywood. 

These papers, which will be published in full in a forthcoming issue of the 
JOURNAL, describe methods and instruments which have been developed for 
analysis of the various vibration components present in airplane structures. 
The complex wave forms are recorded on standard motion picture sound nega- 
tives during flight. After proper development, these films are analyzed elec- 
trically, making possible a complete analysis on the ground, thereby reducing 
materially the time devoted to flight tests, and simplifying the process of analysis 
of complex wave forms. 

The meeting was held in the Review Room of ERPI in Hollywood. 



Dec., 1944 SOCIETY ANNOUNCEMENTS 445 

PROGRESS MEDAL AND JOURNAL AWARDS 

The 1944 gold Progress Medal of the vSociety was awarded to Mr. John George 
Capstaff of the Kastinan Kodak Research Laboratories, Rochester, N. Y., in 
recognition of his pioneer work in the fields of amateur, professional, and color 
cinematography. The medal was presented by President Herbert Griffin at the 
Dinner- Dance held on October 17, during the 56th Semi-Annual Technical Con- 
ference of the Society in New York. Dr. C. E. K. Mees, Vice- President in charge 
of Research, Eastman Kodak Company, read the citation reviewing the high- 
lights of Mr. Capstaff 's work in these fields. 

The 1944 Journal Award, given annually for the most outstanding paper 
originally published in the JOURNAL for the preceding year, was made to Messrs. 
J.I. Crab tree, G. T. Eaton, and L. E. Muehler for their paper, "The Removal of 
Hypo and Silver Salts from Photographic Materials as Affected by the Com- 
position of the Processing Solutions," published in the July, 1943, issue. Cer- 
tificates were presented by Mr. Griffin following the reading of a citation sketch- 
ing the careers of the authors by Mr. Glenn E. Matthews. 

Honorable mention for general excellence was given to Messrs. C. E. Ives 
and E. W. Jensen for their paper, "The Effect of Developer Agitation on Density 
Uniformity and Rate of Development," published in February, 1943. 

The address made by Mr. Griffin during these proceedings, as well as the cita- 
tions and remarks of recipients of the awards, will be published in the January, 
1945, JOURNAL. 



JOURNAL 

OF THE SOCIETY OF 

MOTION PICTURE ENGINEERS 






AUTHOR AND CLASSIFIED 
INDEXES 

VOLUME 43 
JUNE-DECEMBER, 1944 



AUTHOR INDEX, VOLUME 43 

JULY TO DECEMBER, 1944 



Author 

BAUERNSCHMIDT, J. E. 
BOON, J. L. 

BOYER, M. R. 
CALHOUN, J. M. 

CHERTOK, S. L. 
CLIFFORD, H. R. 
COOPER, W. 

CRABTREE, J. I. 

(and HENN, R. W.) 
CRICKS, R. H. 

DICKINSON, E. A. 
(and STROCK, R. O.) 

DRESSER, J. 
DUNNING, C. H. 
DYKE, F. T. 
EDOUART, F. 
FIELDS, J. L. 
FRAYNE, J. G. 
GOLDFARB, L. R. 

GOLDNER, O. 

GORISCH, R. 

(and GORLICH, P.) 
448 



Title No. Page 

It is to Laugh 5 (Nov.) 366 

The Eastman High-Speed Camera, 

Type III 5 (Nov.) 321 

Report of Subcommittee C on 

16-Mm Laboratory Practice 1 (July) 21 

The Physical Properties and Dimen- 
sional Behavior of Motion Picture 
Film 4 (Oct.) 227 

Some Fundamental Considerations 

in Military Amplifier Design 1 (July) 10 

United States Naval Photographic 

Science Laboratories 6 (Dec.) 405 

Film in Television: Television 
Production as Viewed by a Mo- 
tion Picture Producer 2 (Aug.) 73 

Calcium Scums and Sludges in 

Photography 6 (Dec.) 426 

The Requirements of Modern Pro- 
jector Design 2 (Aug.) 129 

Western Electric Recording System 
U. S. Naval Photographic 
Science Laboratory 6 (Dec.) 379 

Treatment of Navy Slide Films for 

Psychologic Impact 5 (Nov.) 352 

Sixteen-Mm Color to 35-Mm Black- 

and-White 3 (Sept.) 174 

An AAF Portable Sound Recording 

Unit 5 (Nov.) 327 

High-Efficiency Stereopticon Pro- 
jector for Color Background Shots 2 (Aug.) 97 

A New Mobile Recording Unit for 

Studio and Location Work 1 (July) 51 

Noise-Reduction Anticipation Cir- 
cuits 5 (Nov.) 313 

Getting the Most for the Navy 

Training Film Dollar 5 (Nov.) 357 

The Training Film Formula 5 (Nov.) 334 

Reproduction of Color Film Sound 

Records 3 (Sept.) 206 



Dec., 1944 



INDEX 



11'.) 



Author 

GORLICH, P. 

(and G6RISCH, R.) 

HARRISON, E. B. 

HENN, R. W. 

(and CRABTREE, J. I.) 

HYNDMAN, D. E. 
JENSEN, H. R. 

KIMBALL, H. R. 

(and MILLER, W. C.) 

LANSING, J. B. 
MAURER, J. A. 

McKiE, R. V. 
MCNAIR, J. W. 



MILLER, W. C. 

(and KIMBALL, H. R.) 

MINER, W. C. 
MORGAN, E. K. 

OFFENHAUSER, W. H., JR. 
ROBERTS, H. B. 



STROCK, R. O. 

(and*DicKiNSON, E. A.) 

THOMPSON, B. H. 



THOMPSON, L. 



Title 

Reproduction of Color Film Sound 
Records 

High-Quality Communication and 

Power Transformers 
Calcium Scums and Sludges in 

Photography 

Report of the Engineering Vice- 
President on Standardization 

The Camera versus the Microphone 
in Training Film Production 

A Rerecording Console, Associated 
Circuits, and Constant B Equal- 



The Duplex Loudspeaker 



B 



Report of Subcommittee 
16-Mm Sound 

Commercial Processing of 16-Mm 
Variable Area 

The Role of the American Standards 
Association in War Standardiza- 
tion 

A Rerecording Console, Associated 

Circuits, and Constant B Equal- 
izers 

Film in Television: Television Pro- 
duction as Viewed by a Radio 
Broadcaster 

Duplication of Kodachrome Trans- 
parencies for Background Projec- 
tion 

A Plan for Preserving 16-Mm 
Originals of Educational Films 

The Training Film an Instrument 
for the Control of Human Be- 
havior 

Western Electric Recording System 
U. S. Naval Photographic 
Science Laboratory 

Kodachrome Transfer 

Present and Proposed Uses of Plas- 
tics in the Motion Picture Indus- 
try 

What to Expect of Direct 16-Mm 



No. Page 

3 (Sept.) 206 

3 (Sept.) 155 

6 (Dec.) 426 

1 (July) 1 

5 (Nov.) 372 

3 (Sept.) 187 

3 (Sept.) 168 

1 (July) 19 

6 (Dec.) 414 

1 (July) 5 

3 (Sept.) 187 

2 (Aug.) 79 

2 (Aug.) 93 

6 (Dec.) 418 

5 (Nov.) 344 



6 (Dec.) 379 
2 (Aug.) 95 



2 (Aug.) 106 

3 (Sept.) 178 



450 

TOWNSLEY, M. G. 



TUTTLE, C. 

WATSON, E. M. 

t 
WHITTENTON, J. M. 

ZIMMERMAN, A. G. 



INDEX 

A Film for Measuring Projector 

Steadiness 1 (July) 30 

The Effect of Lamp Filament Posi- 
tion on Projection Screen Bright- 
ness Uniformity 1 (July) 37 

A Method for Measuring the Steadi- 
ness of Motion Picture Cameras 1 (July) 45 

Note on the Evaluation of Photo- 
graphic Speed from Sensitometric 
Data 1 (July) 59 

Aids for Pictorially Analyzing High- 
Speed Action 4 (Oct.) 267 

Fast Motion Analysis as an Aid to 

Organized Invention 4 (Oct.) 289 

Report of Subcommittee G on Ex- 
posure Meters 1 (July) 25 

Report of Subcommittee D on 

16-Mm Projection 1 (July), 23 

War Standards for Photographic 
Equipment Speed Military In- 
struction 2 (Aug.) 115 



CLASSIFIED INDEX, VOLUME 43 
JULY TO DECEMBER, 1944 

American Standards Association 

(See also Standards and War Committee on Photography and Cinematography 

Z52) 
The Role of the American Standards Association in War Standardization, 

J. W. McNair, No. 1 (July), p. 5. 
American Motion Picture Standards: Z22.34 1944, p. 124; Z22.36 1944, 

p. 125; Z22.37 1944, p. 126; Z22.38 1944, p. 127; Z22.39 1944, p. 128; 

No. 2 (Aug.). 

Amplifiers 

Some Fundamental Considerations in Military Amplifier Design, S. L. Chertok, 
No. 1 (July), p. 10. 

Apparatus 

A New Mobile Recording Unit for Studio and Location Work, J. L. Fields, 

No. 1 (July), p. 51. 
High-Efficiency Stereopticon Projector for Color Background Shots, F. Edouart, 

No. 2 (Aug.), p. 97. 
A Rerecording Console, Associated Circuits, and Constant B Equalizers, 

W. C. Miller and H. R. Kimball, No. 3 (Sept.), P- 187. 
An AAF Portable Sound Recording Unit, F. T. Dyke, No. 5 (Nov.), p. 327. 

Atlantic Coast Section (See SMPE Activities and Announcements) 
Background Projection (See Projection, Background) 

Book Review 

A Guide to the Literature of Photography and Related Subjects, No. 3 (Sept.), 
p. 214. 

Cameras 

A Method for Measuring the Steadiness of Motion Picture Cameras, M. G. 

Townsley, No. 1 (July), p. 45. 
Aids for Pictorially Analyzing High-Speed Action, E. M. Watson, No. 4 

(Oct.), p. 267. 

Technical News, No. 4 (Oct.), p. 303. 
The Eastman High-Speed Camera, Type III, J. L. Boon, No. 5 (Nov.), p. 321. 

Cinematography 

Technical News, No. 4 (Oct.), p. 303. 

Cinematography, High-Speed 

Aids for Pictorially Analyzing High-Speed Action, E. M. Watson, No. 4 (Oct.), 
p. 267. 

451 



452 INDEX Vol 43, No. 6 

Fast Motion Analysis as an Aid to Organized Invention, E. M. Watson, No. 4 

(Oct.), p. 289. 
The Eastman High-Speed Camera, Type III, J. L. Boon, No. 5 (Nov.), p. 321. 

Color 

Technical News, No. 1 (July), p. 67; No. 4 (Oct.), p. 303. 

Duplication of Kodachrome Transparencies for Background Projection, E. K. 

Morgan, No. 2 (Aug.), p. 93. 

Kodachrome Transfer, B. H. Thompson, No. 2 (Aug.), p. 95. 
High- Efficiency Stereopticon Projector for Color Background Shots, F. Edouart, 

No. 2 (Aug.), p. 97. 
Sixteen-Mm Color to 35-Mm Black-and- White, C. H. Dunning, No. 3 (Sept.), 

p. 174. 
Reproduction of Color Film Sound Records, R. Gorisch and P. Gorlich, No. 3 

(Sept.), p. 206. 

Current Literature 
No. 2 (Aug.), p. 149; No. 3 (Sept.), p. 214; No. 5 (Nov.), p. 377. 

Developing (See Processing) 

Educational Motion Pictures 

(See also Sixteen-Mm Motion Pictures and Training Films') 
A Plan for Preserving 16-Mm Originals of Educational Films, W. H. Offen- 
hauser, Jr., No. 6 (Dec.), p. 418. 

Engineering Vice-President, SMPE 

Report of the Engineering Vice-President on Standardization, D. E. Hyndman, 
No. 1 (July), p. 1. 

Exposure Meters (See Photometry) 

Film, General 

Note on the Evaluation of Photographic Speed from Sensitometric Data, 

C. Tuttle, No. 1 (July), p. 59. 
Film in Television: Television Production as Viewed by a Motion Picture 

Producer, W. Cooper, No. 2 (Aug.), p. 73. 
Film in Television : Television Production as Viewed by a Radio Broadcaster, 

W. C. Miner, No. 2 (Aug.), p. 79. 
The Physical Properties and Dimensional Behavior of Motion Picture Film, 

J. M. Calhoun, No. 4 (Oct.), P- 227. 

Film Preservation and Storage 

The Physical Properties and Dimensional Behavior of Motion Picture Film, 

J. M. Calhoun, No. 4 (Oct.), p. 227. 
A Plan for Preserving 16-Mm Originals of Educational Films, W. H. Offen- 

hauser, Jr., No. 6 (Dec.), p. 418. 

High-Speed Photography (See Cinematography, High-Speed) 

Illumination, Projection 

The Effect of Lamp Filament Position on Projection Screen Brightness Uni- 
formity, M. G. Townsley, No. 1 (July), p. 37. 



Dec., 1944 INDEX 453 

Illumination, Studio 

Technical News, No. 1 (July), p. 67. 

Journal Award (See SMPE Activities and Announcements') 

Laboratory Practice, General 
(See also Processing) 
Technical News, No. 1 (July), p. 67. 
United States Naval Photographic Science Laboratories, H. R. Clifford, No. 6 

(Dec.), p. 405. 
Calcium Scums and Sludges in Photography, R. W. Heim and J. I. Crabtree, 

No. 6 (Dec.), p. 426. 

Laboratory Practice, 16-Mm 

Report of Subcommittee C on 16-Mm Laboratory Practice, M. R. Boyer, 

No. 1 (July), p. 21. 

What to Expect of Direct 16-Mm, L. Thompson, No. 3 (Sept.), p. 178. 
Commercial Processing of 16-Mm Variable Area, R. V. McKie, No. 6 (Dec.), 

p. 414. 

Loudspeakers 

The Duplex Loudspeaker, J. B. Lansing, No. 3 (Sept.), p. 168. 

Motion Picture Photography (See Cinematography} 
Motion Studies (See Time Studies} 

Navy, U. S. 

(See also Training Films} 

Western Electric Recording System U. S. Naval Photographic Science 

Laboratory, R. O. Strock and E. A. Dickinson, No. 6 (Dec.), p. 379. 
United States Naval Photographic Science Laboratories, H. R. Clifford, No. 6 

(Dec.), p. 405. 

Obituary 

M. A. Durand, No. 1 (July), p. 72; J. S. MacLeod, No. 2 (Aug.), p. 150; 
W. L. Douden, No. 5 (Nov.), p. 378. 

Pacific Coast Section (See SMPE Activities and Announcements) 

Photometry 

Report of Subcommittee G on Exposure Meters, J. M. Whittentou, No. 1 
(July), p. 25. 

Plastics 

Present and Proposed Uses of Plastics in the Motion Picture Industry, B. H. 
Thompson, No. 2 (Aug.), p. 106. 

Preservation (See Film Preservation and Storage} 

Printing 

Sixteen-Mm Color to 35-Mm Black-and-White, C. H. Dunning, No. 3 (Sept.), 
p. 174. 



454 INDEX Vol 43, No. 6 

Processing 

Reproduction of Color Film Sound Records, R. Gorisch and P. Gorlich, No. 3 

(Sept.), P. 206. 
The Physical Properties and Dimensional Behavior of Motion Picture Film, 

J. M. Calhoun, No. 4 (Oct.), p. 227. 
Commercial Processing of 16-Mm Variable Area, R. V. McKie, No. 6 (Dec.), 

p. 414. 
Calcium Scums and Sludges in Photography, R. W. Henn and J. I. Crabtree, 

No. 6 (Dec.), p. 426. 

Production 

A New Mobile Recording Unit for Studio and Location Work, J. L. Fields, 

No. 1 (July), p. 51. 
Present and Proposed Uses of Plastics in the Motion Picture Industry, B. H. 

Thompson, No. 2 (Aug.), p. 106. 

An AAF Portable Sound Recording Unit, F. T. Dyke, No. 5 (Nov.), p. 327. 
Western Electric Recording System U. S. Navy Photographic Science 

Laboratory, R. O. Strock and E. A. Dickinson, No. 6 (Dec.), p. 379. 
United States Naval Photographic Science Laboratories, H. R. Clifford, No. 6 

(Dec.), p. 405. 

Progress Medal Award (See SMPE Activities and Announcements) 

Projection, 16-Mm 

Report of Subcommittee D on 16-Mm Projection, A. G. Zimmerman, No. 1 
(July), p. 23. 

The Effect of Lamp Filament Position on Projection Screen Brightness Uni- 
formity, M. G. Townsley, No. 1 (July), p. 37. 

Projection, Background 

Duplication of Kodachrome Transparencies for Background Projection, E. K. 

Morgan, No. 2 (Aug.), p. 93. 
High-Efficiency Stereopticon Projector for Color Background Shots, F. Edouart, 

No. 2 (Aug.), p. 97. 

Projectors, 16-Mm 

Report of Subcommittee D on 16-Mm Projection, A. G. Zimmerman, No. 1 

(July), p. 23. 

A Film for Measuring Projector Steadiness, M. G. Townsley, No. 1 (July), 
p. 30. 

Projectors, 35-Mm 

The Requirements of Modern Projector Design, R. H. Cricks, No. 2 (Aug.), 
p. 129. 

Recording (See Sound Recording) 

Rerecording (See Sound Recording) 

Screen Brightness (See Illumination, Projection) 



Dec., 1944 INDEX 455 

Sensitometry 

Note on the Evaluation of Photographic Speed from Sensitometric Data, 
C. Tuttle, No. 1 (July), p. 59. 

Sixteen-Mm Motion Pictures 
Sixteen-Mm Color to 35-Mm Black-aiid- White, C. H. Dunning, No. 3 (Sept.), 

p. 174. 

What to Expect of Direct 16-Mm, L. Thompson, No. 3 (Sept.), p. 178. 
Commercial Processing of 16-Mm Variable Area, R. V. McKie, No. 6 (Dec.), 

p. 414. 
A Plan for Preserving 16-Mm Originals of Educational Films, W. H. Offen- 

hauser, Jr., No. 6 (Dec.), p. 418. 

Slide Films 

Treatment of Navy Slide Films for Psychologic Impact, J. Dresser, No. 5 
(Nov.), p. 352. 

SMPE Activities and Announcements 

Amendments of By-Laws, No. 3 (Sept.), p. 219; No. 6 (Dec.), p. 442. 
Atlantic Coast Section: 

Meeting, May 24 No. 1 (July), p. 72; Meeting, Sept. 27 No. 5 (Nov.), 

p. 378. 

Back Issues of Journal, Announcement No. 6 (Dec.), p. 444. 
Employment Service, Announcement No. 6 (Dec.), p. 442. 
Fifty-Sixth Semi-Annual Technical Conference : 

Committees and Tentative Program, No. 2 (Aug.), p. 151; No. 3 (Sept.), 

p. 216. 

Journal Award, No. 6 (Dec.), p. 445. 

Officers, Governors, and Section Managers for 1945-46, No. 6 (Dec.), p. 443. 
Pacific Coast Section: 

Meeting, June 6 No. 1 (July), p. 72; Meeting, Nov. 1 No. 6 (Dec.), p. 444. 
Personnel of SMPE Committees, No. 3 (Sept.), p. 221; No. 4 (Oct.), p. 305. 
Progress Medal Award, No. 6 (Dec.), p. 445. 
Report of the Engineering Vice-President on Standardization, D. E. Hyndman, 

No. 1 (July), p. 1. 

Sound Recording 

A New Mobile Recording Unit for Studio and Location Work, J. L. Fields, 

No. 1 (July), p. 51. 

Technical News, No. 1 (July), p. 67; No. 4 (Oct.), p. 303. 
A Rerecording Console, Associated Circuits, and Constant B Equalizers, 

W. C. Miller and H. R. Kimball, No. 3 (Sept.), p. 187. 
Reproduction of Color Film Sound Records, R. Gorisch and P. Gorlich, No. 3 

(Sept.), p. 206. 

Noise-Reduction Anticipation Circuits, J. G. Frayne, No. 5 (Nov.), p. 313. 
An AAF Portable Sound Recording Unit, F. T. Dyke, No. 5 (Nov.), p. 327. 
Western Electric Recording System U. S. Naval Photographic Science 

Laboratory, R. O. Strock and E. A. Dickinson, No. 6 (Dec.), p. 379. 
Commercial Processing of 16-Mm Variable Area, R. V. McKie, No. 6 (Dec.), 

p. 414. 



456 INDEX Vol 43, No. 6 

Sound Reproduction 

The Duplex Loudspeaker, J. B. Lansing, No. 3, (Sept.), p. 168. 
Reproduction of Color Film Sound Records, R. Gorisch and P. Gorlich, No. 3 
(Sept.), p. 206. 

Standards 

Report of the Engineering Vice-President on Standardization, D. E. Hyndman, 

No. 1 (July), p. 1. 
The Role of the American Standards Association in War Standardization, 

No. 1 (July), p. 5. 
Some Fundamental Considerations in Military Amplifier Design, S. L. Chertok, 

No. 1 (July), p. 10. 
Report of Subcommittee B on 16-Mm Sound, J. A. Maurer, No. 1 (July), 

p. 19. 
Report of Subcommittee C on 16-Mm Laboratory Practice, M. R. Boyer, 

No. 1 (July), p. 21. 
Report of Subcommittee D on 16-Mm Projection, A. G. Zimmerman, No. 1 

(July), p. 23. 
Report of Subcommittee G on Exposure Meters, J. M. Whittenton, No. 1 

(July), p. 25. 
A Film for Measuring Projector Steadiness, M. G. Townsley, No. 1 (July), 

p. 30. 
War Standards for Photographic Equipment Speed Military Instruction, 

A. G. Zimmerman, No. 2 (Aug.), p. 115. 
American Motion Picture Standards: Z22.34 1944, p. 124; Z22.36 1944, 

p. 125; Z22.37 1944, p. 126; Z22.38 1944, p. 127; Z22.39 1944, p. 128; 

No. 2 (Aug.). 

Studios (See Production} 

Technical News 

No. 1 (July), p. 67; No. 4 (Oct.), p. 303. 

Television 

Film in Television: Television Production as Viewed by a Motion Picture 

Producer, W. Cooper, No. 2 (Aug.), p. 73. 
Film in Television : Television Production as Viewed by a Radio Broadcaster, 

W. C. Miner, No. 2 (Aug.), p. 79. 
Technical News, No. 4 (Oct.), p. 303. 

Test Films 

Report of Subcommittee B on 16-Mm Sound, J. A. Maurer, No. 1 (July), 

p. 19. 
A Film for Measuring Projector Steadiness, M. G. Townsley, No. 1 (July), 

p. 30. 

Time Studies 

Aids for Pictorially Analyzing High-Speed Action, E. M. Watson, No. 4 

(Oct.), p. 267. 
Fast Motion Analysis as an Aid to Organized Invention, E. M. Watson, No. 4 

(Oct.), P. 289. 



Dec., 1944 INDEX 457 

Training Films 

The Training Film Formula, O. Goldner, No. 5 (Nov.), p. 334. 

The Training Film an Instrument for the Control of Human Behavior, 

H. B. Roberts, No. 5 (Nov.), p. 344. 
Treatment of Navy Slide Films for Psychologic Impact, J. Dresser, No. 5 

(Nov.), p. 352. 
Getting the Most for the Navy Training Film Dollar, L. R. Goldfarb, No. 5 

(Nov.), p. 357. 

It Is to Laugh, J. E. Bauernschmidt, No. 5 (Nov.), p. 366. 
The Camera versus the Microphone in Training Film Production, H. R. Jensen, 

No. 5 (Nov.), p. 372. 
United States Naval Photographic Science Laboratories, H. R. Clifford, No. 6 

(Dec.), p. 405. 

Transformers 

High-Quality Communication and Power Transformers, E. B. Harrison, No. 3 
(Sept.), p. 155. 

Transparencies (See Color} 

War Committee on Photography and Cinematography-Z52 
(See also American Standards Association and Standards) 
Report of the Engineering Vice-President on Standardization, D. E. Hyndman, 

No. 1 (July), p. 1. 
Report of Subcommittee B on 16-Mm Sound, J. A. Maurer, No. 1 (July), 

p. 19. 
Report of Subcommittee C on 16-Mm Laboratory Practice, M. R. Boyer, 

No. 1 (July), p. 21. 
Report of Subcommittee D on 16-Mm Projection, A. G. Zimmerman, No. 1 

(July), p. 23. 
Report of Subcommittee G on Exposure Meters, J. M. Whittenton, No. 1 

(July), p. 25. 
A Film for Measuring Projector Steadiness, M. G. Townsley, No. 1 (July), 

p. 30. 
War Standards for Photographic Equipment Speed Military Instruction, 

A. G. Zimmerman, No. 2 (Aug.), p. 115. 



COMMITTEES OF THE SOCIETY 

(Correct to November 15} 



ADMISSIONS. To pass upon all applications for membership, applications for transfer and 
to review the Student and Associate membership list periodically for possible transfers to the 
Associate and Active grades, respectively. The duties of each committee are limited to applica- 
tions and transfers originating in the geographic area covered. 

;' (East Coast) 

A. S. DICKINSON, Chairman 

28 West 44th St. 
New York 18, N. Y. 

M. R. BOYER JAMES FRANK, JR. D. E. HYNDMAN 

H. D. BRADBURY GEORGE FRIEDL, JR. HARRY RUBIN 

(West Coast) 
EMERY HUSE, Chairman 

6706 Santa Monica Blvd. 
Hollywood 38, Calif. 

C. W. HANDLE Y W. A. MUELLER 

H. W. MOYSE H. W. REMERSHIED 

BOARD OF EDITORS. To pass upon the suitability of all material submitted for publica- 
tion, or for presentation at conventions, and publish the JOURNAL. 

A. C. DOWNES, Chairman 
Box 6087 
Cleveland 1, Ohio 

J. I. CRABTREE A. M. GUNDELFINGER C. R. KEITH 

A. N. GOLDSMITH C. W. HANDLEY E. W. KELLOGG 

A. C. HARDY 

CINEMATOGRAPHY. To survey the field of motion picture photography in an en- 
deavor to bring before the Society any information on current or future practice, and also to 
continually review this field for possibilities of standardization of any specific procedure. 

J. W. BOYLE, Chairman 

1207 N. Mansfield Ave. 
Hollywood, Calif. 

C. G. CLARKE *ARTHUR MILLER ARTHUR REEVES 

KARL FREUND JOSEPH RUTTENBERG 

COLOR. To survey the field of color in motion picture photography in an endeavor to bring 
before the Society any information on current or future practice, and also to continually review 
this field for possibilities of standardization of any specific procedure. 

R. M. EVANS, Chairman 

Research .Laboratory- 
Eastman Kodak Co. 
Rochester^, N. Y. 

F. T. BOWDITCH A. M. GUNDELFINGER 

L. E. CLARK A. C. HARDY 



* Advisory Member. 



COMMITTEES OF THE SOCIETY 

CONVENTION. To assist the Convention Vice-President in the responsibilities pertaining 
to arrangements and details of the Society's technical conventions. 

W. C. KUNZMANN, Chairman 

Box 6087 
Cleveland 1, Ohio 

J. G. FRAYNE SYLVAN HARRIS O. F. NEU 

"JULIUS HABER H. F. HEIDEGGER R. O. STROCK 

EXCHANGE PRACTICE. To survey the field of exchange practice in an endeavor to bring 
before the Society any information on current or future practice, and also to continually review 
this field for possibilities of standardization of any specific procedure. 

A. S. DICKINSON G. K. HADDOW N. F. OAKLEY 

*T. FAULKNER SYLVAN HARRIS A. W. SCHWALBERG 

G. R. GIROUX L. B. ISAAC J. SICHELMAN 

H. C. KAUFMAN 

FELLOW MEMBERSHIP. To consider qualifications of Active members as candidates for 
elevation to Fellow members, and to submit such nominations to the Board of Governors. 

EMERY HUSE, Chairman 

6706 Santa Monica Blvd. 
Hollywood 38, Calif. 

M. R. BOYER A. N. GOLDSMITH W. C. KUNZMANN 

A. S. DICKINSON HERBERT GRIFFIN L. L. RYDER 

A. C. DOWNES C. W. HANDLEY E. A. WILLIFORD 

D. E. HYNDMAN 

HISTORICAL AND MUSEUM. To collect facts and assemble data relating to the historical 
development of the motion picture industry, to encourage pioneers to place their work on record 
in the form of papers for publication in the JOURNAL, and to place in suitable depositories equip- 
ment pertaining to the industry. 

J. E. ABBOTT, Chairman 

11 West 53d St. 
New York 19, N. Y. 

O. B. DEPUE RICHARD GRIFFITH TERRY RAMSAYE 

HONORARY MEMBERSHIP. To diligently search for candidates who through their 
basic inventions or outstanding accomplishments have contributed to the advancement of the 
motion picture industry and are thus worthy of becoming Honorary members of the Society. 

E. A. WILLIFORD, Chairman 

30 East 42d St. 
New York 17, N. Y. 

J. I. CRABTREE EMERY HUSE 

A. N. GOLDSMITH L. L. RYDER 

JOURNAL AWARD. To recommend to the Board of Governors the author or authors of 
the most outstanding paper originally published in the JOURNAL during the preceding calendar 
year to receive the Society's Journal Award. 

SYLVAN HARRIS, Chairman 

8621 Georgia Ave. . 

Silver Spring, Md. 

F. G. ALBIN C. R. KEITH 

J. G. FRAYNE J. A. MAURER 



* Advisory Member. 



COMMITTEES OF THE SOCIETY 

LABORATORY PRACTICE. To survey the field of motion picture laboratory practice in 
an endeavor to bring before the Society any information on current or future practice, and also 
to continually review this field for possibilities of standardization of any specific procedure. 

H. E. WHITE, Chairman 

Room 813 

350 Madison Ave. 

New York 17, N. Y. 

A. C. BLANEY G. H. GIBSON J. M. NICKOLAUS 

L. A. BONN EMERY HUSE N. F. OAKLEY 

A. W. COOK T. M. INGMAN W. H. OFFENHAUSER, JR. 

O. B. DEPUE C. L. LOOTENS V. C. SHANER 

R. O. DREW *A. J. MILLER J. H. SPRAY 

J. A. DUBRAY H. W. MOYSE J. F. VAN LEUVEN 

J. G. FRAYNE J. R. WILKINSON 

MEMBERSHIP AND SUBSCRIPTION. To solicit new members, obtain nonmember sub- 
scriptions for the JOURNAL, and to arouse general interest in the activities of the Society and its 
publications. 

JAMES FRANK, JR., Chairman 

356 West 44th St. 
New York 18, N. Y. 

T. C. BARROWS E. R. GEIB W. A. MUELLER 

J. G. BRADLEY L. T. GOLDSMITH H. B. SANTEE 

KARL BRENKERT SYLVAN HARRIS G. E. SAWYER 

G. A. CHAMBERS L. B. ISAAC W. L. THAYER 

L. W. CHASE W. C. KUNZMANN E. O. WILSCHKE 

J. P. CORCORAN S. A. LUKES W. V. WOLFE 

J. G. FRAYNE G. E. MATTHEWS C. R. WOOD, SR. 
G. C. MISENER 

NONTHEATRICAL EQUIPMENT. To survey the field of nontheatrical motion picture 
equipment in an endeavor to bring before the Society any information on current or future prac- 
tice, and also to continually review this field for possibilities of standardization of any specific 
procedure. 

J. A. MAURER, Chairman 

117 East 24th St. 
New York 10, N. Y. 

*F. L. BRETHAUER R. C. HOLSLAG *T. J. RESS 

F. E. CARLSON R. KINGSLAKE L. T. SACHTLEBEN 

JOHN CHRISTIE D. F. LYMAN A. SHAPIRO 

R.O.DREW W.H. OFFENHAUSER, JR. D. G. SMITH 

F. M. HALL M. W. PALMER M. G. TOWNSLEY 

J. A. HAMMOND A. G. ZIMMERMAN 

PAPERS. To solicit papers, and provide the program for semi-annual conventions, and make 
available to local sections for their meetings papers presented at national conventions. 

C. R. DAILY, Chairman BARTON KREUZER, Vice-chairman 

5451 Marathon St. RCA Victor Division 

Hollywood 38, Calif. Radio Corp. of America 

Camden, N. J. 

F. T. BOWDITCH J. G. FRAYNE H. W. MOYSE 

G. A. CHAMBERS . C. R. KEITH W. H. OFFENHAUSER, JR. 
F. L. EICH E. W. KELLOGG V. C. SHANER 

R. E. FARNHAM G. E. MATTHEWS S. P. SOLOW 

J. L. FORREST P. A. McGuiRE D. R. WHITE 

JAMES FRANK, JR. W. V. WOLFE 



* Advisory Member. 



COMMITTEES OF THE SOCIETY 

PRESERVATION OF FILM. To survey the field for methods of storing and preserving mo- 
tion picture film in an endeavor to bring before the Society any information on current or future 
practice, and also to continually review this field for possibilities of standardization of any specific 
procedure. 

J. G. BRADLEY, Chairman 

The National Archives 
Washington 25, D. C. 

J. E. ABBOTT J. L. FORREST *W. F. KELLEY 

J. I. CRABTREB C. L. GREGORY TERRY RAMSAYE 

A. S. DICKINSON V. B. SEASE 



PROCESS PHOTOGRAPHY. To survey the field of process photography in an endeavor 
to bring before the Society any information on current or future practice, and also to continually 
review this field for possibilities of standardization of any specific procedure. 

WILLIAM THOMAS, Chairman 

851 Monterey Rd. 
Glendale, Calif. 

F. R. ABBOTT *F. M. FALGE GROVER LAUBE 

A. H. BOLT C. W. HANDLEY G. H. WORRALL 

W. C. HOCH 



PROGRESS. To prepare an annual report on progress in the motion picture industry. 

G. A. CHAMBERS, Chairman 

Naval Air Station, PSL 
Anacostia, D. C. 

F. T. BOWDITCH J. A. DUBRAY G. E. MATTHEWS 

G. L. DIMMICK M. S. LESHING D. R. WHITE 



PROGRESS MEDAL AWARD. To recommend to the Board of Governors a candidate who 
by his inventions, research or development has contributed in a significant manner to the 
advancement of motion picture technology, and is deemed worthy of receiving the Progress 
Medal Award of the Society. 

J. I. CRABTREE, Chairman 

Research Laboratory 
Eastman Kodak Co. 
Rochester 4, N. Y. 

O. B. DEPUE J. A. MAURER 

G. E. MATTHEWS L. L. RYDER 



PUBLICITY. To assist the Convention Vice-President in the release of publicity material 
concerning the Society's semi-annual technical conventions. 

*JULIUS HABER, Chairman 

RCA Victor Division 
Radio Corp. of America 
Camden, N. J. 

G. A. CHAMBERS *HAROLD DESFOR G. R. GIROUX 

C. R. DAILY P. A. McGuiRE 



* Advisory Member. 



COMMITTEES OF THE SOCIETY 



SOUND. To survey the field of motion picture sound recording and reproducing in an en- 
deavor to bring before the Society any information on current or future practice, and also to con- 
tinually review this field for possibilities of standardization of any specific procedure. 



W. V. WOLFE, Chairman 

515 N. Alta Drive 
Beverly Hills, Calif. 

M. C. BATSEL 
D. J. BLOOMBERG 

B. B. BROWN 

F. E. CAHILL, JR. 

C. R. DAILY 

L. T. GOLDSMITH 



C. R. KEITH, Vice-Chairman 
195 Broadway 
New York 7, N. Y. 



E. H. HANSEN 
L. B. ISAAC 

J. P. LlVADARY 
G. T. LORANCE 

J. A. MAURER 
W. C. MILLER 
K. F. MORGAN 



W. A. MUELLER 
HARRY RUBIN 
G. E. SAWYER 
S. P. SOLOW 
F. R. WILSON 
*E. C. ZRENNER 



STANDARDS. To survey the various fields or branches of the motion picture industry in an 
endeavor to bring before the Society any information on current or future practice or methods 
that would lead to possibilities of standardization of any specific procedure. 



J. M. ANDREAS 
P. H. ARNOLD 
HERBERT BARNETT 
M. C. BATSEL 
M. R. BOYER 
F. E. CARLSON 
*T. H. CARPENTER 
E. K. CARVER 

H. B. CUTHBERTSON 

L. W. DAVEE 

J. A. DUBRAY 

A. F. EDOUART 



F. T. BOWDITCH, Chairman 

Box 6087 
Cleveland 1, Ohio 



J. L. FORREST 
A. N. GOLDSMITH 
L. T. GOLDSMITH 
IRL GOSHAW 
HERBERT GRIFFIN 
A. C. HARDY 
D. B. JOY 
C. R. KEITH 
P. J. LARSEN 

R. G. LlNDERMAN 

C. L. LOOTENS 



J. A. MAURER 

G. A. MITCHELL 

W. H. OFFENHAUSER, JR. 

G. F. RACKETT 

W. B. RAYTON 

HARRY RUBIN 

L. T. SACHTLEBEN 

OTTO SANDVIK 

LLOYD THOMPSON 

J. F. VAN LEUVEN 

H. E. WHITE 

A. G. ZIMMERMAN 



STUDIO LIGHTING. To survey the field of motion picture studio lighting in an endeavor 
to bring before the Society any information on current or future practice, and also to continually 
review this field for possibilities of standardization of any specific procedure. 



J. W. BOYLE 
H. J. CHANON 



C. W HANDLE Y, Chairman 

I960 West 84th St. 
Los Angeles 44, Calif. 

R. E. FARNHAM 



KARL FREUND 
W. W. LOZIER 



TECHNICAL NEWS. To survey the fields of production, distribution, and exhibition of 
motion pictures, and allied industries, to obtain technical news items for publication in the 
JOURNAL. 

A. C. BLANEY, Chairman 

1016 N. Sycamore St. 
Hollywood 38, Calif. 



J. W. BOYLE 
J. I. CRABTREE 

A. M. GUNDELFINGER 



C. W. HANDLEY 
EMERY HUSE 
H. R. LUBCKE 



K. F. MORGAN 

H. W. REMERSHIED 

WILLIAM THOMAS 



Advisory Member. 



COMMITTEES OF THE SOCIETY 



TELEVISION. Technical consideration of the uses of motion picture television service; 
technical consideration of the phases of television which affect origination, transmission, dis- 
tribution, and reproduction of theater television. 



F. G. ALBIN 
R. B. AUSTRIAN 
R. L. CAMPBELL 
E. D. COOK 
C. E. DEAN 
A. N. GOLDSMITH 
T. T. GOLDSMITH 
HERBERT GRIFFIN 



P. C. GOLDMARK, Chairman 

485 Madison Ave. 
New York 22, N. Y. 

P. H. HISS 

C. F. HORSTMAN 

L. B. ISAAC 
A. G. JENSEN 
P. J. LARSEN 
C. C. LARSON 
NATHAN LEVINSON 
H. R. LUBCKE 



*I. G. MALOFF 
J. A. MAURER 
PIERRE MERTZ 

*PAUL RAIBOURN 
OTTO SANDVIK 
R. E, SHELBY 
E. I. SPONABLE 
H. E. WHITE 



TEST FILM QUALITY. To supervise the quality of prints of test films prepared by the 
Society. 

F. R. WILSON C. F. HORSTMAN 

THEATER ENGINEERING. The Committee on Theater Engineering comprises the 
membership of the four subcommittees listed below and is under the general chairmanship of 
DR. ALFRED N. GOLDSMITH, 597 Fifth Ave., New York 17, N. Y. 



Subcommittee on Film Projection Practice. To make recommendations and prepare specifi- 
cations for the operation, maintenance, and servicing of motion picture projection equipment, 
projection rooms, film storage facilities, and stage arrangements as they affect screen dimen- 
sions, placement, and the maintenance of loudspeakers. 

L. B. ISAAC, Chairman 
M. D. O'BRIEN, Secretary 

1540 Broadway 
New York 19, N. Y. 



HENRY ANDERSON 
T. C. BARROWS 
H. D. BEHR 
M. F. BENNETT 
KARL BRENKERT 
F. E. CAHILL, JR. 
C. C. DASH 
L. W. DAVEE 
A. S. DICKINSON 



J. K. ELDERKIN 
JAMES FRANK, JR. 
R. R. FRENCH 
E. R. GEIB 
ADOLPH GOODMAN 
HERBERT GRIFFIN 
SYLVAN HARRIS 
J. J. HOPKINS 
C. F. HORSTMAN 
I. JACOBSEN 



*J. H. LlTTENBERG 

E. R. MORIN 
J. R. PRATER 
HARRY RUBIN 
J. J. SEFING 
R. O. WALKER 
V. A. WELMAN 
H. E. WHITE 
A. T. WILLIAMS 



Subcommittee on Television Projection Practice. To make recommendations and prepare 
specifications for the construction, installation, maintenance, and servicing of equipment for 
projecting television pictures in the theater, as well as the projection room arrangements neces- 
sary for such equipment, and such picture-dimensional and screen-characteristic matters as 
may be involved in theater television presentation. 

L. B. ISAAC, Chairman 
M. D. O'BRIEN, Secretary 

1540 Broadway 
New York 19, N. Y. 



F. G. ALBIN 

G. S. APPELGATE 
HERBERT BARNETT 
T. C. BARROWS 
M. F. BENNETT 

F. E. CAHILL, JR. 
L. W. DAVEE 
JAMES FRANK, JR. 

* Advisory Member. 



ADOLPH GOODMAN 
HERBERT GRIFFIN 
J. J. HOPKINS 
C. F. HORSTMAN 
C. R. KEITH 
J. J. KOHLER 
P. J. LARSEN 

*J. H. LlTTENBERG 

J. A. MAURER 



R. H. McCULLOUGH 

L. J. PATTON 
A. J. RADEMACHER 
HARRY RUBIN 
A. G. SMITH 
E. I. SPONABLE 
*FRANK SUTTON 
V. A. WELMAN 



COMMITTEES OF THE SOCIETY 

Subcommittee on Screen Brightness. To make recommendations, prepare specifications 
and test methods for determining and standardizing the brightness of the motion picture screen 
image at various parts of the screen, and for specific means or devices in the projection room 
adapted to the control or improvement of screen brightness. 

F. E. CARLSON, Chairman 

Nela Park 
Cleveland 12, Ohio 

HERBERT BARNETT W. F. LITTLE C. M. TUTTLE 

E. R. GEIB W. B. RAYTON H. E. WHITE 

SYLVAN HARRIS A. T. WILLIAMS 

Subcommittee on Theater Engineering, Construction, and Operation. To deal with the 
technical methods and equipment of motion picture theaters in relation to their contribution for 
the physical comfort and safety of patrons so far as can be enhanced by correct theater design, 
construction, and operation of equipment. 

HENRY ANDERSON, Chairman 

1501 Broadway 

New York 18, N. Y. 

(Committee under Organization) 



MEMBERS OF THE SOCIETY 

LOST IN THE SERVICE OF 

THEIR COUNTRY 



FRANKLIN C. GILBERT 



ISRAEL H. TILLES 



HOT SMPE TEST FILMS AVAILABLE 



Test films prepared under the supervision of the Projection Practice 
Committee of the Society of Motion Picture Engineers have been remade 
with new titles, new test targets, and fuller explanations for their use. 
These films are now available to theaters, review rooms, exchanges, labo- 
ratories, etc., for testing the performance of projectors. Both the 
SMPE 35-mm and 16-mm Visual Test Films have been completely re- 
made. The 16-mm Sound Test Film negative has been rerecorded from 
the 35-mm Sound Test Film, with new titles added to both films. 

Only complete reels, as described below, are available (not short sec- 
tions or single frequencies) . The prices given include shipping charges to 
all points within the United States. Delivery is approximately 2 weeks 
after receipt of orders. 

35-MM SOUND FILM: Approximately 500 ft long, consisting of re- 
cordings of several speaking voices, piano, and orchestra; buzz-track; 
fixed frequencies for focusing sound optical system; fixed frequencies at 
constant level, for determining reproducer characteristics, frequency 
range, flutter, sound-track adjustment, 60- or 96-cycle modulation, etc. 

The recorded frequency range of the voice and music extends to 10,000 
cps; the constant-amplitude frequencies are in 15 steps from 50 cps to 
10,000 cps. Price $37.50 each. 

35-MM VISUAL FILM: Approximately 500 ft long, consisting of spe- 
cial targets with the aid of which travel-ghost, marginal and radial lens 
aberrations, definition, picture jump, and film weave may be detected 
and corrected. Price $37.50 each. 

16-MM SOUND FILM: Approximately 400 ft long, consisting of re- 
cordings of several speaking voices, piano, and orchestra; buzz-track; 
fixed frequencies for focusing sound optical system; fixed frequencies at 
constant level, for determining reproducer characteristics, frequency 
range, flutter, sound-track adjustment, 60- or 96-cycle modulation, etc. 

The recorded frequency range of the voice and music extends to 6000 
cps ; the constant-amplitude frequencies are in 1 1 steps from 50 cps to 
6000 cps. Price $25.00 each. 

16-MM VISUAL FILM: An optical reduction of the 35-Mm Visual Test 
Film, identical as to contents and approximately 225 ft long. Price 
$25.00 each. 

SOCIETY of MOTION PICTURE ENGINEERS 

MOTtL PENNSYLVANIA NCW YOP.KI, N-Y- TtL. PNN. 6 O62O